31620725 has 6 divisors (see below), whose sum is σ = 39209730. Its totient is φ = 25296560.

The previous prime is 31620709. The next prime is 31620733. The reversal of 31620725 is 52702613.

It can be written as a sum of positive squares in 3 ways, for example, as 4674244 + 26946481 = 2162^2 + 5191^2 .

It is not a de Polignac number, because 31620725 - 2⁴ = 31620709 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31620694 and 31620703.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 632390 + ... + 632439.

It is an arithmetic number, because the mean of its divisors is an integer number (6534955).

Almost surely, 2^31620725 is an apocalyptic number.

It is an amenable number.

31620725 is a deficient number, since it is larger than the sum of its proper divisors (7589005).

31620725 is a wasteful number, since it uses less digits than its factorization.

31620725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1264839 (or 1264834 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 26.

The square root of 31620725 is about 5623.2308328931. The cubic root of 31620725 is about 316.2209271967.

The spelling of 31620725 in words is "thirty-one million, six hundred twenty thousand, seven hundred twenty-five".