21123332120 has 128 divisors (see below), whose sum is σ = 52715681280. Its totient is φ = 7553280000.

The previous prime is 21123332119. The next prime is 21123332149. The reversal of 21123332120 is 2123332112.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 21123332092 and 21123332101.

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, 17587520 + ... + 17588720.

It is an arithmetic number, because the mean of its divisors is an integer number (411841260).

Almost surely, 2^21123332120 is an apocalyptic number.

21123332120 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 21123332120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26357840640).

21123332120 is an abundant number, since it is smaller than the sum of its proper divisors (31592349160).

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

21123332120 is a wasteful number, since it uses less digits than its factorization.

21123332120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1857 (or 1853 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

Adding to 21123332120 its reverse (2123332112), we get a palindrome (23246664232).

The spelling of 21123332120 in words is "twenty-one billion, one hundred twenty-three million, three hundred thirty-two thousand, one hundred twenty".