31220403220 has 12 divisors (see below), whose sum is σ = 65562846804. Its totient is φ = 12488161280.

The previous prime is 31220403169. The next prime is 31220403239. The reversal of 31220403220 is 2230402213.

It can be written as a sum of positive squares in 2 ways, for example, as 16491182724 + 14729220496 = 128418^2 + 121364^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 780510061 + ... + 780510100.

It is an arithmetic number, because the mean of its divisors is an integer number (5463570567).

Almost surely, 2^31220403220 is an apocalyptic number.

It is an amenable number.

31220403220 is an abundant number, since it is smaller than the sum of its proper divisors (34342443584).

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

31220403220 is a wasteful number, since it uses less digits than its factorization.

31220403220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1561020170 (or 1561020168 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 19.

Adding to 31220403220 its reverse (2230402213), we get a palindrome (33450805433).

The spelling of 31220403220 in words is "thirty-one billion, two hundred twenty million, four hundred three thousand, two hundred twenty".