31720905216 has 1080 divisors, whose sum is σ = 129201168096. Its totient is φ = 7274741760.

The previous prime is 31720905173. The next prime is 31720905221. The reversal of 31720905216 is 61250902713.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 1379169781 + ... + 1379169803.

Almost surely, 2^31720905216 is an apocalyptic number.

31720905216 is a gapful number since it is divisible by the number (36) 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 31720905216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (64600584048).

31720905216 is an abundant number, since it is smaller than the sum of its proper divisors (97480262880).

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

31720905216 is a wasteful number, since it uses less digits than its factorization.

31720905216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114 (or 59 counting only the distinct ones).

The product of its (nonzero) digits is 22680, while the sum is 36.

The spelling of 31720905216 in words is "thirty-one billion, seven hundred twenty million, nine hundred five thousand, two hundred sixteen".