31131521532 has 120 divisors (see below), whose sum is σ = 82878014912. Its totient is φ = 10187337600.

The previous prime is 31131521503. The next prime is 31131521543. The reversal of 31131521532 is 23512513113.

31131521532 is a `hidden beast` number, since 3 + 1 + 131 + 521 + 5 + 3 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 31131521496 and 31131521505.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 13062813 + ... + 13065195.

Almost surely, 2^31131521532 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31131521532, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41439007456).

31131521532 is an abundant number, since it is smaller than the sum of its proper divisors (51746493380).

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

31131521532 is a wasteful number, since it uses less digits than its factorization.

31131521532 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3121 (or 3110 counting only the distinct ones).

The product of its digits is 2700, while the sum is 27.

The spelling of 31131521532 in words is "thirty-one billion, one hundred thirty-one million, five hundred twenty-one thousand, five hundred thirty-two".