31530421220 has 48 divisors (see below), whose sum is σ = 70620666480. Its totient is φ = 11783614464.

The previous prime is 31530421213. The next prime is 31530421229. The reversal of 31530421220 is 2212403513.

It can be written as a sum of positive squares in 8 ways, for example, as 6488624704 + 25041796516 = 80552^2 + 158246^2 .

It is not an unprimeable number, because it can be changed into a prime (31530421229) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 291875 + ... + 385034.

It is an arithmetic number, because the mean of its divisors is an integer number (1471263885).

Almost surely, 2^31530421220 is an apocalyptic number.

It is an amenable number.

31530421220 is an abundant number, since it is smaller than the sum of its proper divisors (39090245260).

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

31530421220 is a wasteful number, since it uses less digits than its factorization.

31530421220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 677072 (or 677070 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 23.

Adding to 31530421220 its reverse (2212403513), we get a palindrome (33742824733).

The spelling of 31530421220 in words is "thirty-one billion, five hundred thirty million, four hundred twenty-one thousand, two hundred twenty".