315681 has 4 divisors (see below), whose sum is σ = 420912. Its totient is φ = 210452.

The previous prime is 315677. The next prime is 315691. The reversal of 315681 is 186513.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 186513 = 3 ⋅62171.

It is a cyclic number.

It is not a de Polignac number, because 315681 - 2² = 315677 is a prime.

It is a super-2 number, since 2×315681² = 199308987522, which contains 22 as substring.

It is a D-number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 315681.

It is not an unprimeable number, because it can be changed into a prime (315631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52611 + ... + 52616.

It is an arithmetic number, because the mean of its divisors is an integer number (105228).

2³¹⁵⁶⁸¹ is an apocalyptic number.

It is an amenable number.

315681 is a deficient number, since it is larger than the sum of its proper divisors (105231).

315681 is a wasteful number, since it uses less digits than its factorization.

315681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105230.

The product of its digits is 720, while the sum is 24.

The square root of 315681 is about 561.8549634915. The cubic root of 315681 is about 68.0899185311.

The spelling of 315681 in words is "three hundred fifteen thousand, six hundred eighty-one".