31520745660 has 192 divisors, whose sum is σ = 90811736064. Its totient is φ = 8167200000.

The previous prime is 31520745637. The next prime is 31520745667. The reversal of 31520745660 is 6654702513.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31520745667) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 125580535 + ... + 125580785.

It is an arithmetic number, because the mean of its divisors is an integer number (472977792).

Almost surely, 2^31520745660 is an apocalyptic number.

31520745660 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 31520745660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45405868032).

31520745660 is an abundant number, since it is smaller than the sum of its proper divisors (59290990404).

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

31520745660 is a wasteful number, since it uses less digits than its factorization.

31520745660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 664 (or 662 counting only the distinct ones).

The product of its (nonzero) digits is 151200, while the sum is 39.

The spelling of 31520745660 in words is "thirty-one billion, five hundred twenty million, seven hundred forty-five thousand, six hundred sixty".