31971620 has 12 divisors (see below), whose sum is σ = 67140444. Its totient is φ = 12788640.

The previous prime is 31971613. The next prime is 31971631. The reversal of 31971620 is 2617913.

It can be written as a sum of positive squares in 2 ways, for example, as 16777216 + 15194404 = 4096^2 + 3898^2 .

It is a super-4 number, since 4×31971620⁴ (a number of 31 digits) contains 4444 as substring.

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, 799271 + ... + 799310.

It is an arithmetic number, because the mean of its divisors is an integer number (5595037).

Almost surely, 2^31971620 is an apocalyptic number.

It is an amenable number.

31971620 is an abundant number, since it is smaller than the sum of its proper divisors (35168824).

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

31971620 is a wasteful number, since it uses less digits than its factorization.

31971620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1598590 (or 1598588 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 29.

The square root of 31971620 is about 5654.3452317665. The cubic root of 31971620 is about 317.3863275469.

The spelling of 31971620 in words is "thirty-one million, nine hundred seventy-one thousand, six hundred twenty".