331909987 has 16 divisors (see below), whose sum is σ = 353882880. Its totient is φ = 310619232.

The previous prime is 331909979. The next prime is 331909999. The reversal of 331909987 is 789909133.

It is not a de Polignac number, because 331909987 - 2³ = 331909979 is a prime.

It is a super-2 number, since 2×331909987² = 220328478940680338, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 331909987.

It is not an unprimeable number, because it can be changed into a prime (331909927) 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, 375448 + ... + 376330.

It is an arithmetic number, because the mean of its divisors is an integer number (22117680).

Almost surely, 2^331909987 is an apocalyptic number.

331909987 is a deficient number, since it is larger than the sum of its proper divisors (21972893).

331909987 is a wasteful number, since it uses less digits than its factorization.

331909987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1242.

The product of its (nonzero) digits is 367416, while the sum is 49.

The square root of 331909987 is about 18218.3969382600. The cubic root of 331909987 is about 692.3729730905.

The spelling of 331909987 in words is "three hundred thirty-one million, nine hundred nine thousand, nine hundred eighty-seven".