318512681 has 4 divisors (see below), whose sum is σ = 320650500. Its totient is φ = 316374864.

The previous prime is 318512639. The next prime is 318512699. The reversal of 318512681 is 186215813.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 210685225 + 107827456 = 14515^2 + 10384^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-318512681 is a prime.

It is a super-2 number, since 2×318512681² = 202900655915615522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (318512611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1068686 + ... + 1068983.

It is an arithmetic number, because the mean of its divisors is an integer number (80162625).

Almost surely, 2^318512681 is an apocalyptic number.

It is an amenable number.

318512681 is a deficient number, since it is larger than the sum of its proper divisors (2137819).

318512681 is a wasteful number, since it uses less digits than its factorization.

318512681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2137818.

The product of its digits is 11520, while the sum is 35.

The square root of 318512681 is about 17846.9235724256. The cubic root of 318512681 is about 682.9290327538.

The spelling of 318512681 in words is "three hundred eighteen million, five hundred twelve thousand, six hundred eighty-one".