31081998 has 16 divisors (see below), whose sum is σ = 63844560. Its totient is φ = 10080576.

The previous prime is 31081987. The next prime is 31082017. The reversal of 31081998 is 89918013.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 69783 + ... + 70226.

It is an arithmetic number, because the mean of its divisors is an integer number (3990285).

Almost surely, 2^31081998 is an apocalyptic number.

31081998 is an abundant number, since it is smaller than the sum of its proper divisors (32762562).

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

31081998 is a wasteful number, since it uses less digits than its factorization.

31081998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140051.

The product of its (nonzero) digits is 15552, while the sum is 39.

The square root of 31081998 is about 5575.1231376536. The cubic root of 31081998 is about 314.4147965830.

The spelling of 31081998 in words is "thirty-one million, eighty-one thousand, nine hundred ninety-eight".