31131013320 has 96 divisors (see below), whose sum is σ = 110373606720. Its totient is φ = 7546911360.

The previous prime is 31131013307. The next prime is 31131013339. The reversal of 31131013320 is 2331013113.

It is a happy number.

31131013320 is a `hidden beast` number, since 31 + 1 + 310 + 1 + 3 + 320 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 31131013293 and 31131013302.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3926724 + ... + 3934643.

It is an arithmetic number, because the mean of its divisors is an integer number (1149725070).

Almost surely, 2^31131013320 is an apocalyptic number.

31131013320 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31131013320 is an abundant number, since it is smaller than the sum of its proper divisors (79242593400).

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

31131013320 is a wasteful number, since it uses less digits than its factorization.

31131013320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7861395 (or 7861388 counting only the distinct ones).

The product of its (nonzero) digits is 162, while the sum is 18.

Adding to 31131013320 its reverse (2331013113), we get a palindrome (33462026433).

The spelling of 31131013320 in words is "thirty-one billion, one hundred thirty-one million, thirteen thousand, three hundred twenty".