123131021101020 has 144 divisors (see below), whose sum is σ = 376302154999680. Its totient is φ = 32588517610368.

The previous prime is 123131021101019. The next prime is 123131021101043. The reversal of 123131021101020 is 20101120131321.

123131021101020 is a `hidden beast` number, since 1 + 231 + 310 + 2 + 1 + 101 + 0 + 20 = 666.

It is a super-2 number, since 2×123131021101020² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 123131021100984 and 123131021101002.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 79370827 + ... + 80907293.

It is an arithmetic number, because the mean of its divisors is an integer number (2613209409720).

Almost surely, 2^{123131021101020} is an apocalyptic number.

123131021101020 is a gapful number since it is divisible by the number (10) 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 123131021101020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (188151077499840).

123131021101020 is an abundant number, since it is smaller than the sum of its proper divisors (253171133898660).

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

123131021101020 is a wasteful number, since it uses less digits than its factorization.

123131021101020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1539824 (or 1539819 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

Adding to 123131021101020 its reverse (20101120131321), we get a palindrome (143232141232341).

The spelling of 123131021101020 in words is "one hundred twenty-three trillion, one hundred thirty-one billion, twenty-one million, one hundred one thousand, twenty".