31997663880 has 512 divisors, whose sum is σ = 123863040000. Its totient is φ = 6430814208.

The previous prime is 31997663879. The next prime is 31997663903. The reversal of 31997663880 is 8836679913.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 25017081 + ... + 25018359.

It is an arithmetic number, because the mean of its divisors is an integer number (241920000).

Almost surely, 2^31997663880 is an apocalyptic number.

31997663880 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 31997663880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (61931520000).

31997663880 is an abundant number, since it is smaller than the sum of its proper divisors (91865376120).

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

31997663880 is a wasteful number, since it uses less digits than its factorization.

31997663880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1421 (or 1417 counting only the distinct ones).

The product of its (nonzero) digits is 11757312, while the sum is 60.

The spelling of 31997663880 in words is "thirty-one billion, nine hundred ninety-seven million, six hundred sixty-three thousand, eight hundred eighty".