31213900 has 36 divisors (see below), whose sum is σ = 69926080. Its totient is φ = 12081600.

The previous prime is 31213879. The next prime is 31213901. The reversal of 31213900 is 931213.

It is not an unprimeable number, because it can be changed into a prime (31213901) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1935 + ... + 8134.

Almost surely, 2^31213900 is an apocalyptic number.

It is an amenable number.

31213900 is an abundant number, since it is smaller than the sum of its proper divisors (38712180).

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

31213900 is a wasteful number, since it uses less digits than its factorization.

31213900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10114 (or 10107 counting only the distinct ones).

The product of its (nonzero) digits is 162, while the sum is 19.

The square root of 31213900 is about 5586.9401285498. The cubic root of 31213900 is about 314.8589273399.

It can be divided in two parts, 3121 and 3900, that added together give a triangular number (7021 = T₁₁₈).

The spelling of 31213900 in words is "thirty-one million, two hundred thirteen thousand, nine hundred".