311985 has 16 divisors (see below), whose sum is σ = 554880. Its totient is φ = 166320.

The previous prime is 311981. The next prime is 312007. The reversal of 311985 is 589113.

It is not a de Polignac number, because 311985 - 2² = 311981 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 311985.

It is not an unprimeable number, because it can be changed into a prime (311981) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1021 + ... + 1290.

It is an arithmetic number, because the mean of its divisors is an integer number (34680).

2³¹¹⁹⁸⁵ is an apocalyptic number.

It is an amenable number.

311985 is a deficient number, since it is larger than the sum of its proper divisors (242895).

311985 is a wasteful number, since it uses less digits than its factorization.

311985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2325 (or 2319 counting only the distinct ones).

The product of its digits is 1080, while the sum is 27.

The square root of 311985 is about 558.5561744355. The cubic root of 311985 is about 67.8231419161.

It can be divided in two parts, 311 and 985, that added together give a 4-th power (1296 = 6⁴).

The spelling of 311985 in words is "three hundred eleven thousand, nine hundred eighty-five".