31997666400 has 432 divisors, whose sum is σ = 121767362640. Its totient is φ = 7276953600.

The previous prime is 31997666333. The next prime is 31997666473. The reversal of 31997666400 is 466679913.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 28341036 + ... + 28342164.

It is an arithmetic number, because the mean of its divisors is an integer number (281868895).

Almost surely, 2^31997666400 is an apocalyptic number.

31997666400 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 31997666400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (60883681320).

31997666400 is an abundant number, since it is smaller than the sum of its proper divisors (89769696240).

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

31997666400 is a wasteful number, since it uses less digits than its factorization.

31997666400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1407 (or 1387 counting only the distinct ones).

The product of its (nonzero) digits is 1469664, while the sum is 51.

The spelling of 31997666400 in words is "thirty-one billion, nine hundred ninety-seven million, six hundred sixty-six thousand, four hundred".