31981212 has 36 divisors (see below), whose sum is σ = 83452096. Its totient is φ = 10316160.

The previous prime is 31981193. The next prime is 31981217. The reversal of 31981212 is 21218913.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31981217) 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, 13213 + ... + 15444.

Almost surely, 2^31981212 is an apocalyptic number.

It is an amenable number.

31981212 is an abundant number, since it is smaller than the sum of its proper divisors (51470884).

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

31981212 is a wasteful number, since it uses less digits than its factorization.

31981212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28698 (or 28693 counting only the distinct ones).

The product of its digits is 864, while the sum is 27.

The square root of 31981212 is about 5655.1933653943. The cubic root of 31981212 is about 317.4180647068.

The spelling of 31981212 in words is "thirty-one million, nine hundred eighty-one thousand, two hundred twelve".