31213023220 has 48 divisors (see below), whose sum is σ = 66263496768. Its totient is φ = 12349532160.

The previous prime is 31213023203. The next prime is 31213023221. The reversal of 31213023220 is 2232031213.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31213023221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 665172 + ... + 710548.

It is an arithmetic number, because the mean of its divisors is an integer number (1380489516).

Almost surely, 2^31213023220 is an apocalyptic number.

It is an amenable number.

31213023220 is an abundant number, since it is smaller than the sum of its proper divisors (35050473548).

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

31213023220 is a wasteful number, since it uses less digits than its factorization.

31213023220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45760 (or 45758 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 19.

Adding to 31213023220 its reverse (2232031213), we get a palindrome (33445054433).

The spelling of 31213023220 in words is "thirty-one billion, two hundred thirteen million, twenty-three thousand, two hundred twenty".