31791777256920 has 256 divisors, whose sum is σ = 99317775767040. Its totient is φ = 8133804822528.

The previous prime is 31791777256919. The next prime is 31791777256927. The reversal of 31791777256920 is 2965277719713.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31791777256927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1893824767 + ... + 1893841553.

It is an arithmetic number, because the mean of its divisors is an integer number (387960061590).

Almost surely, 2^{31791777256920} is an apocalyptic number.

31791777256920 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 31791777256920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49658887883520).

31791777256920 is an abundant number, since it is smaller than the sum of its proper divisors (67525998510120).

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

31791777256920 is a wasteful number, since it uses less digits than its factorization.

31791777256920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22754 (or 22750 counting only the distinct ones).

The product of its (nonzero) digits is 70013160, while the sum is 66.

The spelling of 31791777256920 in words is "thirty-one trillion, seven hundred ninety-one billion, seven hundred seventy-seven million, two hundred fifty-six thousand, nine hundred twenty".