56531281 has 2 divisors, whose sum is σ = 56531282. Its totient is φ = 56531280.

The previous prime is 56531257. The next prime is 56531297. The reversal of 56531281 is 18213565.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 54626881 + 1904400 = 7391^2 + 1380^2 .

It is a cyclic number.

It is not a de Polignac number, because 56531281 - 2⁵ = 56531249 is a prime.

It is a super-2 number, since 2×56531281² = 6391571463001922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (56531081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28265640 + 28265641.

It is an arithmetic number, because the mean of its divisors is an integer number (28265641).

Almost surely, 2^56531281 is an apocalyptic number.

It is an amenable number.

56531281 is a deficient number, since it is larger than the sum of its proper divisors (1).

56531281 is an equidigital number, since it uses as much as digits as its factorization.

56531281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7200, while the sum is 31.

The square root of 56531281 is about 7518.7286824303. The cubic root of 56531281 is about 383.7923161717.

The spelling of 56531281 in words is "fifty-six million, five hundred thirty-one thousand, two hundred eighty-one".