31233031220 has 12 divisors (see below), whose sum is σ = 65589365604. Its totient is φ = 12493212480.

The previous prime is 31233031211. The next prime is 31233031259. The reversal of 31233031220 is 2213033213.

It can be written as a sum of positive squares in 2 ways, for example, as 18965696656 + 12267334564 = 137716^2 + 110758^2 .

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 1561651561 = 31233031220 / (3 + 1 + 2 + 3 + 3 + 0 + 3 + 1 + 2 + 2 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 31233031192 and 31233031201.

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, 780825761 + ... + 780825800.

It is an arithmetic number, because the mean of its divisors is an integer number (5465780467).

Almost surely, 2^31233031220 is an apocalyptic number.

It is an amenable number.

31233031220 is an abundant number, since it is smaller than the sum of its proper divisors (34356334384).

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

31233031220 is a wasteful number, since it uses less digits than its factorization.

31233031220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1561651570 (or 1561651568 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 20.

Adding to 31233031220 its reverse (2213033213), we get a palindrome (33446064433).

The spelling of 31233031220 in words is "thirty-one billion, two hundred thirty-three million, thirty-one thousand, two hundred twenty".