31791698640 has 960 divisors, whose sum is σ = 129398860800. Its totient is φ = 7142473728.

The previous prime is 31791698639. The next prime is 31791698683. The reversal of 31791698640 is 4689619713.

It is a super-3 number, since 3×31791698640³ (a number of 32 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 291666906 + ... + 291667014.

It is an arithmetic number, because the mean of its divisors is an integer number (134790480).

Almost surely, 2^31791698640 is an apocalyptic number.

31791698640 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 31791698640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (64699430400).

31791698640 is an abundant number, since it is smaller than the sum of its proper divisors (97607162160).

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

31791698640 is a wasteful number, since it uses less digits than its factorization.

31791698640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221 (or 196 counting only the distinct ones).

The product of its (nonzero) digits is 1959552, while the sum is 54.

The spelling of 31791698640 in words is "thirty-one billion, seven hundred ninety-one million, six hundred ninety-eight thousand, six hundred forty".