31221211312 has 40 divisors (see below), whose sum is σ = 63752906160. Its totient is φ = 14770863360.

The previous prime is 31221211253. The next prime is 31221211337. The reversal of 31221211312 is 21311212213.

It is a super-2 number, since 2×31221211312² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a self number, because there is not a number n which added to its sum of digits gives 31221211312.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 187038 + ... + 312130.

It is an arithmetic number, because the mean of its divisors is an integer number (1593822654).

Almost surely, 2^31221211312 is an apocalyptic number.

It is an amenable number.

31221211312 is an abundant number, since it is smaller than the sum of its proper divisors (32531694848).

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

31221211312 is a wasteful number, since it uses less digits than its factorization.

31221211312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125941 (or 125935 counting only the distinct ones).

The product of its digits is 144, while the sum is 19.

Adding to 31221211312 its reverse (21311212213), we get a palindrome (52532423525).

Subtracting from 31221211312 its reverse (21311212213), we obtain a palindrome (9909999099).

The spelling of 31221211312 in words is "thirty-one billion, two hundred twenty-one million, two hundred eleven thousand, three hundred twelve".