311988 has 12 divisors (see below), whose sum is σ = 728000. Its totient is φ = 103992.

The previous prime is 311981. The next prime is 312007. The reversal of 311988 is 889113.

It is a tau number, because it is divible by the number of its divisors (12).

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 311988.

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

311988 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12988 + ... + 13011.

2³¹¹⁹⁸⁸ is an apocalyptic number.

It is an amenable number.

311988 is an abundant number, since it is smaller than the sum of its proper divisors (416012).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

311988 is a wasteful number, since it uses less digits than its factorization.

311988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26006 (or 26004 counting only the distinct ones).

The product of its digits is 1728, while the sum is 30.

The square root of 311988 is about 558.5588599244. The cubic root of 311988 is about 67.8233593077.

It can be divided in two parts, 3119 and 88, that multiplied together give a palindrome (274472).

The spelling of 311988 in words is "three hundred eleven thousand, nine hundred eighty-eight".