312981 has 4 divisors (see below), whose sum is σ = 417312. Its totient is φ = 208652.

The previous prime is 312979. The next prime is 312989. The reversal of 312981 is 189213.

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.

It is a cyclic number.

It is not a de Polignac number, because 312981 - 2¹ = 312979 is a prime.

It is a super-2 number, since 2×312981² = 195914212722, which contains 22 as substring.

It is a D-number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 312981.

It is not an unprimeable number, because it can be changed into a prime (312989) 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, 52161 + ... + 52166.

It is an arithmetic number, because the mean of its divisors is an integer number (104328).

2³¹²⁹⁸¹ is an apocalyptic number.

It is an amenable number.

312981 is a deficient number, since it is larger than the sum of its proper divisors (104331).

312981 is a wasteful number, since it uses less digits than its factorization.

312981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104330.

The product of its digits is 432, while the sum is 24.

The square root of 312981 is about 559.4470484326. The cubic root of 312981 is about 67.8952394967.

The spelling of 312981 in words is "three hundred twelve thousand, nine hundred eighty-one".