31972177920 has 384 divisors, whose sum is σ = 106036257600. Its totient is φ = 8219787264.

The previous prime is 31972177891. The next prime is 31972177931. The reversal of 31972177920 is 2977127913.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 31972177920.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 118855546 + ... + 118855814.

Almost surely, 2^31972177920 is an apocalyptic number.

31972177920 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 31972177920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (53018128800).

31972177920 is an abundant number, since it is smaller than the sum of its proper divisors (74064079680).

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

31972177920 is a wasteful number, since it uses less digits than its factorization.

31972177920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425 (or 405 counting only the distinct ones).

The product of its (nonzero) digits is 333396, while the sum is 48.

The spelling of 31972177920 in words is "thirty-one billion, nine hundred seventy-two million, one hundred seventy-seven thousand, nine hundred twenty".