21131032120 has 128 divisors (see below), whose sum is σ = 54151416000. Its totient is φ = 7350497280.

The previous prime is 21131032073. The next prime is 21131032127. The reversal of 21131032120 is 2123013112.

It is a junction number, because it is equal to n+sod(n) for n = 21131032094 and 21131032103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21131032127) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1383244 + ... + 1398436.

Almost surely, 2^21131032120 is an apocalyptic number.

21131032120 is a gapful number since it is divisible by the number (20) 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 21131032120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27075708000).

21131032120 is an abundant number, since it is smaller than the sum of its proper divisors (33020383880).

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

21131032120 is a wasteful number, since it uses less digits than its factorization.

21131032120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15353 (or 15349 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21131032120 its reverse (2123013112), we get a palindrome (23254045232).

The spelling of 21131032120 in words is "twenty-one billion, one hundred thirty-one million, thirty-two thousand, one hundred twenty".