31137972 has 12 divisors (see below), whose sum is σ = 72655296. Its totient is φ = 10379320.

The previous prime is 31137961. The next prime is 31137991. The reversal of 31137972 is 27973113.

It is a happy number.

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

It is a super-4 number, since 4×31137972⁴ (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, 1297404 + ... + 1297427.

It is an arithmetic number, because the mean of its divisors is an integer number (6054608).

Almost surely, 2^31137972 is an apocalyptic number.

It is an amenable number.

31137972 is an abundant number, since it is smaller than the sum of its proper divisors (41517324).

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

31137972 is a wasteful number, since it uses less digits than its factorization.

31137972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2594838 (or 2594836 counting only the distinct ones).

The product of its digits is 7938, while the sum is 33.

The square root of 31137972 is about 5580.1408584372. The cubic root of 31137972 is about 314.6034213079.

It can be divided in two parts, 311 and 37972, that added together give a palindrome (38283).

The spelling of 31137972 in words is "thirty-one million, one hundred thirty-seven thousand, nine hundred seventy-two".