312987 has 18 divisors (see below), whose sum is σ = 467868. Its totient is φ = 186048.

The previous prime is 312979. The next prime is 312989. The reversal of 312987 is 789213.

It is a happy number.

It is not a de Polignac number, because 312987 - 2³ = 312979 is a prime.

It is an Ulam number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 312987.

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 17 ways as a sum of consecutive naturals, for example, 16464 + ... + 16482.

2³¹²⁹⁸⁷ is an apocalyptic number.

312987 is a deficient number, since it is larger than the sum of its proper divisors (154881).

312987 is a wasteful number, since it uses less digits than its factorization.

312987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75 (or 39 counting only the distinct ones).

The product of its digits is 3024, while the sum is 30.

The square root of 312987 is about 559.4524108447. The cubic root of 312987 is about 67.8956733556.

The spelling of 312987 in words is "three hundred twelve thousand, nine hundred eighty-seven".