360 (number)

In mathematics

• 360 is the 13th highly composite number and one of only seven numbers such that no number less than twice as much has more divisors; the others are 1, 2, 6, 12, 60, and 2520 .

• 360 is also the 6th superior highly composite number, the 6th colossally abundant number, a refactorable number, a 5-smooth number, and a Harshad number in decimal since the sum of its digits (9) is a divisor of 360.

• 360 is divisible by the number of its divisors (24), and it is the smallest number divisible by every natural number from 1 to 10, except 7. Furthermore, one of the divisors of 360 is 72, which is the number of primes below it.

• 360 is the sum of twin primes (179 + 181) and the sum of four consecutive powers of three (9 + 27 + 81 + 243).

• The sum of Euler's totient function φ(x) over the first thirty-four integers is 360.

• 360 is a triangular matchstick number.

• 360 is the product of the first two unitary perfect numbers: 60 \times 6 = 360.

• There are 360 even permutations of 6 elements. They form the alternating group A6.

A turn is divided into 360 degrees for angular measurement. is also called a round angle. This unit choice divides round angles into equal sectors measured in integer rather than fractional degrees. Many angles commonly appearing in planimetrics have an integer number of degrees. For a simple non-intersecting polygon, the sum of the internal angles of a quadrilateral always equals 360 degrees.

Integers from 361 to 369

361

361=19^2, centered triangular number, centered octagonal number, centered decagonal number, member of the Mian–Chowla sequence. There are also 361 positions on a standard 19 × 19 Go board.

362

362=2\times181=\sigma_2(19): sum of squares of divisors of 19, Mertens function returns 0, nontotient, noncototient.

363

Main article: 363 (number)

364

364=2^2\times 7\times 13, tetrahedral number, sum of twelve consecutive primes (11 + 13 + 17 + 19 + 23 + 29 + 31 + 37 + 41 + 43 + 47 + 53), Mertens function returns 0, nontotient.

It is a repdigit in bases three (111111), nine (444), twenty-five (EE), twenty-seven (DD), fifty-one (77), and ninety (44); the sum of six consecutive powers of three (1 + 3 + 9 + 27 + 81 + 243); and the twelfth non-zero tetrahedral number.

365

Main article: 365 (number)

365 is the amount of days in a common year. For the common year, see common year.

366

366=2\times 3\times 61, sphenic number, Mertens function returns 0, noncototient, number of complete partitions of 20, 26-gonal and 123-gonal. There are also 366 days in a leap year.

367

367 is a prime number, Perrin number, happy number, prime index prime and a strictly non-palindromic number.

368

368=2^4\times 23. It is also a Leyland number.

369

Main article: 369 (number)

References

Sources

• Wells, D. (1987). The Penguin Dictionary of Curious and Interesting Numbers (p. 152). London: Penguin Group.

References

1. {{Cite OEIS. A002182. Highly composite numbers, definition (1): numbers n where d(n), the number of divisors of n (A000005), increases to a record.
2. "A002201 - OEIS".
3. "A004490 - OEIS".
4. {{Cite OEIS. A045943. Triangular matchstick numbers: a(n) is 3n(n+1)/2
5. {{Cite OEIS. A002827. Unitary perfect numbers: numbers k such that usigma(k) - k equals k.
6. "Centered Triangular Number".
7. {{Cite OEIS
8. {{Cite OEIS
9. {{cite OEIS. A001157
10. {{Cite OEIS. A028442. Numbers k such that Mertens's function M(k) (A002321) is zero
11. "Noncototient".
12. {{Cite OEIS
13. {{Cite OEIS
14. "Sphenic number".
15. {{cite OEIS. A126796. Number of complete partitions of n
16. "Parrin number".
17. {{Cite OEIS. A076980