31157772 has 12 divisors (see below), whose sum is σ = 72701496. Its totient is φ = 10385920.

The previous prime is 31157767. The next prime is 31157779. The reversal of 31157772 is 27775113.

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

It is not an unprimeable number, because it can be changed into a prime (31157779) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1298229 + ... + 1298252.

It is an arithmetic number, because the mean of its divisors is an integer number (6058458).

Almost surely, 2^31157772 is an apocalyptic number.

It is an amenable number.

31157772 is an abundant number, since it is smaller than the sum of its proper divisors (41543724).

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

31157772 is a wasteful number, since it uses less digits than its factorization.

31157772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2596488 (or 2596486 counting only the distinct ones).

The product of its digits is 10290, while the sum is 33.

The square root of 31157772 is about 5581.9147252533. The cubic root of 31157772 is about 314.6700904739.

The spelling of 31157772 in words is "thirty-one million, one hundred fifty-seven thousand, seven hundred seventy-two".