31172028 has 12 divisors (see below), whose sum is σ = 72734760. Its totient is φ = 10390672.

The previous prime is 31171993. The next prime is 31172039. The reversal of 31172028 is 82027113.

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

It is a junction number, because it is equal to n+sod(n) for n = 31171989 and 31172007.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1298823 + ... + 1298846.

It is an arithmetic number, because the mean of its divisors is an integer number (6061230).

Almost surely, 2^31172028 is an apocalyptic number.

It is an amenable number.

31172028 is an abundant number, since it is smaller than the sum of its proper divisors (41562732).

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

31172028 is a wasteful number, since it uses less digits than its factorization.

31172028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2597676 (or 2597674 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 31172028 is about 5583.1915603891. The cubic root of 31172028 is about 314.7180747865.

The spelling of 31172028 in words is "thirty-one million, one hundred seventy-two thousand, twenty-eight".