31131112320 has 960 divisors, whose sum is σ = 139854607200. Its totient is φ = 6459678720.

The previous prime is 31131112303. The next prime is 31131112321. The reversal of 31131112320 is 2321113113.

31131112320 is a `hidden beast` number, since 31 + 1 + 311 + 1 + 2 + 320 = 666.

It is a tau number, because it is divible by the number of its divisors (960).

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 = 31131112293 and 31131112302.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31131112321) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 43908126 + ... + 43908834.

Almost surely, 2^31131112320 is an apocalyptic number.

31131112320 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31131112320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (69927303600).

31131112320 is an abundant number, since it is smaller than the sum of its proper divisors (108723494880).

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

31131112320 is a wasteful number, since it uses less digits than its factorization.

31131112320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 769 (or 737 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

Adding to 31131112320 its reverse (2321113113), we get a palindrome (33452225433).

The spelling of 31131112320 in words is "thirty-one billion, one hundred thirty-one million, one hundred twelve thousand, three hundred twenty".