31131323212 has 24 divisors (see below), whose sum is σ = 59478108480. Its totient is φ = 14139748560.

The previous prime is 31131323191. The next prime is 31131323227. The reversal of 31131323212 is 21232313113.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 213162 + ... + 328177.

It is an arithmetic number, because the mean of its divisors is an integer number (2478254520).

Almost surely, 2^31131323212 is an apocalyptic number.

It is an amenable number.

31131323212 is a deficient number, since it is larger than the sum of its proper divisors (28346785268).

31131323212 is a wasteful number, since it uses less digits than its factorization.

31131323212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 542661 (or 542659 counting only the distinct ones).

The product of its digits is 648, while the sum is 22.

Adding to 31131323212 its reverse (21232313113), we get a palindrome (52363636325).

The spelling of 31131323212 in words is "thirty-one billion, one hundred thirty-one million, three hundred twenty-three thousand, two hundred twelve".