31887471920 has 40 divisors (see below), whose sum is σ = 74151623040. Its totient is φ = 12752709120.

The previous prime is 31887471907. The next prime is 31887471949. The reversal of 31887471920 is 2917478813.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

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, 457121 + ... + 522239.

It is an arithmetic number, because the mean of its divisors is an integer number (1853790576).

Almost surely, 2^31887471920 is an apocalyptic number.

It is an amenable number.

31887471920 is an abundant number, since it is smaller than the sum of its proper divisors (42264151120).

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

31887471920 is a wasteful number, since it uses less digits than its factorization.

31887471920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71253 (or 71247 counting only the distinct ones).

The product of its (nonzero) digits is 677376, while the sum is 50.

The spelling of 31887471920 in words is "thirty-one billion, eight hundred eighty-seven million, four hundred seventy-one thousand, nine hundred twenty".