31121010100020 has 96 divisors (see below), whose sum is σ = 88535652710400. Its totient is φ = 8166174724224.

The previous prime is 31121010099937. The next prime is 31121010100067. The reversal of 31121010100020 is 2000101012113.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 31121010099969 and 31121010100005.

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, 517560 + ... + 7906319.

It is an arithmetic number, because the mean of its divisors is an integer number (922246382400).

Almost surely, 2^{31121010100020} is an apocalyptic number.

31121010100020 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 31121010100020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44267826355200).

31121010100020 is an abundant number, since it is smaller than the sum of its proper divisors (57414642610380).

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

31121010100020 is a wasteful number, since it uses less digits than its factorization.

31121010100020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8424877 (or 8424875 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 12.

Adding to 31121010100020 its reverse (2000101012113), we get a palindrome (33121111112133).

The spelling of 31121010100020 in words is "thirty-one trillion, one hundred twenty-one billion, ten million, one hundred thousand, twenty".