31375897664 has 42 divisors (see below), whose sum is σ = 62987952510. Its totient is φ = 15505070592.

The previous prime is 31375897577. The next prime is 31375897667. The reversal of 31375897664 is 46679857313.

It can be written as a sum of positive squares in only one way, i.e., 22562443264 + 8813454400 = 150208^2 + 93880^2 .

It is not an unprimeable number, because it can be changed into a prime (31375897667) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 13367339 + ... + 13369685.

It is an arithmetic number, because the mean of its divisors is an integer number (1499713155).

Almost surely, 2^31375897664 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 31375897664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31493976255).

31375897664 is an abundant number, since it is smaller than the sum of its proper divisors (31612054846).

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

31375897664 is an frugal number, since it uses more digits than its factorization.

31375897664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4795 (or 2438 counting only the distinct ones).

The product of its digits is 22861440, while the sum is 59.

The spelling of 31375897664 in words is "thirty-one billion, three hundred seventy-five million, eight hundred ninety-seven thousand, six hundred sixty-four".