315566981 has 6 divisors (see below), whose sum is σ = 323078310. Its totient is φ = 308226408.

The previous prime is 315566957. The next prime is 315567019. The reversal of 315566981 is 189665513.

It can be written as a sum of positive squares in only one way, i.e., 315382081 + 184900 = 17759^2 + 430^2 .

It is a de Polignac number, because none of the positive numbers 2^k-315566981 is a prime.

It is a super-2 number, since 2×315566981² = 199165038994908722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (315566921) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 83486 + ... + 87183.

It is an arithmetic number, because the mean of its divisors is an integer number (53846385).

Almost surely, 2^315566981 is an apocalyptic number.

It is an amenable number.

315566981 is a deficient number, since it is larger than the sum of its proper divisors (7511329).

315566981 is an equidigital number, since it uses as much as digits as its factorization.

315566981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170755 (or 170712 counting only the distinct ones).

The product of its digits is 194400, while the sum is 44.

The square root of 315566981 is about 17764.2050483550. The cubic root of 315566981 is about 680.8171987558.

The spelling of 315566981 in words is "three hundred fifteen million, five hundred sixty-six thousand, nine hundred eighty-one".