318912561 has 18 divisors (see below), whose sum is σ = 506337650. Its totient is φ = 193279680.

The previous prime is 318912541. The next prime is 318912589. The reversal of 318912561 is 165219813.

318912561 is a `hidden beast` number, since 3 + 1 + 8 + 91 + 2 + 561 = 666.

It can be written as a sum of positive squares in only one way, i.e., 272250000 + 46662561 = 16500^2 + 6831^2 .

It is not a de Polignac number, because 318912561 - 2⁶ = 318912497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (318912541) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 145336 + ... + 147513.

Almost surely, 2^318912561 is an apocalyptic number.

It is an amenable number.

318912561 is a deficient number, since it is larger than the sum of its proper divisors (187425089).

318912561 is a wasteful number, since it uses less digits than its factorization.

318912561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292877 (or 292863 counting only the distinct ones).

The product of its digits is 12960, while the sum is 36.

The square root of 318912561 is about 17858.1231096664. The cubic root of 318912561 is about 683.2147099792.

The spelling of 318912561 in words is "three hundred eighteen million, nine hundred twelve thousand, five hundred sixty-one".