31981012 has 24 divisors (see below), whose sum is σ = 67725504. Its totient is φ = 12899712.

The previous prime is 31981007. The next prime is 31981021. The reversal of 31981012 is 21018913.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33118 + ... + 34069.

It is an arithmetic number, because the mean of its divisors is an integer number (2821896).

Almost surely, 2^31981012 is an apocalyptic number.

It is an amenable number.

31981012 is an abundant number, since it is smaller than the sum of its proper divisors (35744492).

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

31981012 is a wasteful number, since it uses less digits than its factorization.

31981012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67215 (or 67213 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 25.

The square root of 31981012 is about 5655.1756825054. The cubic root of 31981012 is about 317.4174030293.

Adding to 31981012 its reverse (21018913), we get a palindrome (52999925).

The spelling of 31981012 in words is "thirty-one million, nine hundred eighty-one thousand, twelve".