31311020133220 has 48 divisors (see below), whose sum is σ = 67581973695600. Its totient is φ = 12180673105920.

The previous prime is 31311020133167. The next prime is 31311020133313. The reversal of 31311020133220 is 2233102011313.

It can be written as a sum of positive squares in 8 ways, for example, as 5649663117604 + 25661357015616 = 2376902^2 + 5065704^2 .

It is a junction number, because it is equal to n+sod(n) for n = 31311020133191 and 31311020133200.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 144075525 + ... + 144292684.

It is an arithmetic number, because the mean of its divisors is an integer number (1407957785325).

Almost surely, 2^{31311020133220} is an apocalyptic number.

It is an amenable number.

31311020133220 is an abundant number, since it is smaller than the sum of its proper divisors (36270953562380).

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

31311020133220 is a wasteful number, since it uses less digits than its factorization.

31311020133220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 288368368 (or 288368366 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 22.

Adding to 31311020133220 its reverse (2233102011313), we get a palindrome (33544122144533).

The spelling of 31311020133220 in words is "thirty-one trillion, three hundred eleven billion, twenty million, one hundred thirty-three thousand, two hundred twenty".