31997057400 has 960 divisors, whose sum is σ = 140394228480. Its totient is φ = 6560870400.

The previous prime is 31997057329. The next prime is 31997057459. The reversal of 31997057400 is 475079913.

31997057400 is a `hidden beast` number, since 3 + 1 + 9 + 9 + 70 + 574 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 140956087 + ... + 140956313.

It is an arithmetic number, because the mean of its divisors is an integer number (146243988).

Almost surely, 2^31997057400 is an apocalyptic number.

31997057400 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 31997057400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (70197114240).

31997057400 is an abundant number, since it is smaller than the sum of its proper divisors (108397171080).

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

31997057400 is a wasteful number, since it uses less digits than its factorization.

31997057400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 386 (or 368 counting only the distinct ones).

The product of its (nonzero) digits is 238140, while the sum is 45.

The spelling of 31997057400 in words is "thirty-one billion, nine hundred ninety-seven million, fifty-seven thousand, four hundred".