31131132320 has 24 divisors (see below), whose sum is σ = 73547300484. Its totient is φ = 12452452864.

The previous prime is 31131132313. The next prime is 31131132353. The reversal of 31131132320 is 2323113113.

It can be written as a sum of positive squares in 2 ways, for example, as 31033754896 + 97377424 = 176164^2 + 9868^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 31131132292 and 31131132301.

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 3 ways as a sum of consecutive naturals, for example, 97284629 + ... + 97284948.

Almost surely, 2^31131132320 is an apocalyptic number.

It is an amenable number.

31131132320 is an abundant number, since it is smaller than the sum of its proper divisors (42416168164).

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

31131132320 is a wasteful number, since it uses less digits than its factorization.

31131132320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194569592 (or 194569584 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 20.

Adding to 31131132320 its reverse (2323113113), we get a palindrome (33454245433).

The spelling of 31131132320 in words is "thirty-one billion, one hundred thirty-one million, one hundred thirty-two thousand, three hundred twenty".