21120121020120 has 64 divisors (see below), whose sum is σ = 63504692064000. Its totient is φ = 5619203027328.

The previous prime is 21120121020073. The next prime is 21120121020139. The reversal of 21120121020120 is 2102012102112.

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 21120121020120.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 200404050 + ... + 200509409.

It is an arithmetic number, because the mean of its divisors is an integer number (992260813500).

Almost surely, 2^{21120121020120} is an apocalyptic number.

21120121020120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21120121020120 is an abundant number, since it is smaller than the sum of its proper divisors (42384571043880).

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

21120121020120 is a wasteful number, since it uses less digits than its factorization.

21120121020120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 400913912 (or 400913908 counting only the distinct ones).

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

Adding to 21120121020120 its reverse (2102012102112), we get a palindrome (23222133122232).

The spelling of 21120121020120 in words is "twenty-one trillion, one hundred twenty billion, one hundred twenty-one million, twenty thousand, one hundred twenty".