21121122120 has 512 divisors, whose sum is σ = 77909852160. Its totient is φ = 4478976000.

The previous prime is 21121122107. The next prime is 21121122137. The reversal of 21121122120 is 2122112112.

It is a super-2 number, since 2×21121122120² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21121122120.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 77937585 + ... + 77937855.

It is an arithmetic number, because the mean of its divisors is an integer number (152167680).

Almost surely, 2^21121122120 is an apocalyptic number.

21121122120 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 21121122120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38954926080).

21121122120 is an abundant number, since it is smaller than the sum of its proper divisors (56788730040).

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

21121122120 is a wasteful number, since it uses less digits than its factorization.

21121122120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 437 (or 433 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21121122120 its reverse (2122112112), we get a palindrome (23243234232).

The spelling of 21121122120 in words is "twenty-one billion, one hundred twenty-one million, one hundred twenty-two thousand, one hundred twenty".