31213880 has 16 divisors (see below), whose sum is σ = 70231320. Its totient is φ = 12485536.

The previous prime is 31213879. The next prime is 31213901. The reversal of 31213880 is 8831213.

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, 390134 + ... + 390213.

Almost surely, 2^31213880 is an apocalyptic number.

It is an amenable number.

31213880 is an abundant number, since it is smaller than the sum of its proper divisors (39017440).

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

31213880 is a wasteful number, since it uses less digits than its factorization.

31213880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 780358 (or 780354 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 31213880 is about 5586.9383386610. The cubic root of 31213880 is about 314.8588600923.

The spelling of 31213880 in words is "thirty-one million, two hundred thirteen thousand, eight hundred eighty".