31707985920 has 192 divisors, whose sum is σ = 109245296160. Its totient is φ = 7804944384.

The previous prime is 31707985891. The next prime is 31707985937. The reversal of 31707985920 is 2958970713.

It is a tau number, because it is divible by the number of its divisors (192).

It is a super-2 number, since 2×31707985920² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 359662 + ... + 439058.

Almost surely, 2^31707985920 is an apocalyptic number.

31707985920 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 31707985920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (54622648080).

31707985920 is an abundant number, since it is smaller than the sum of its proper divisors (77537310240).

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

31707985920 is a wasteful number, since it uses less digits than its factorization.

31707985920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79440 (or 79420 counting only the distinct ones).

The product of its (nonzero) digits is 952560, while the sum is 51.

The spelling of 31707985920 in words is "thirty-one billion, seven hundred seven million, nine hundred eighty-five thousand, nine hundred twenty".