31020320220 has 24 divisors (see below), whose sum is σ = 86856896784. Its totient is φ = 8272085376.

The previous prime is 31020320213. The next prime is 31020320239. The reversal of 31020320220 is 2202302013.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 31020320220.

It is a congruent number.

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, 258502609 + ... + 258502728.

It is an arithmetic number, because the mean of its divisors is an integer number (3619037366).

Almost surely, 2^31020320220 is an apocalyptic number.

31020320220 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31020320220 is an abundant number, since it is smaller than the sum of its proper divisors (55836576564).

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

31020320220 is a wasteful number, since it uses less digits than its factorization.

31020320220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 517005349 (or 517005347 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 15.

Adding to 31020320220 its reverse (2202302013), we get a palindrome (33222622233).

The spelling of 31020320220 in words is "thirty-one billion, twenty million, three hundred twenty thousand, two hundred twenty".