31861812 has 12 divisors (see below), whose sum is σ = 74344256. Its totient is φ = 10620600.

The previous prime is 31861801. The next prime is 31861813. The reversal of 31861812 is 21816813.

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

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 31861812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31861813) 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, 1327564 + ... + 1327587.

Almost surely, 2^31861812 is an apocalyptic number.

It is an amenable number.

31861812 is an abundant number, since it is smaller than the sum of its proper divisors (42482444).

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

31861812 is a wasteful number, since it uses less digits than its factorization.

31861812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2655158 (or 2655156 counting only the distinct ones).

The product of its digits is 2304, while the sum is 30.

The square root of 31861812 is about 5644.6268255749. The cubic root of 31861812 is about 317.0225514446.

The spelling of 31861812 in words is "thirty-one million, eight hundred sixty-one thousand, eight hundred twelve".