21002121110120 has 128 divisors (see below), whose sum is σ = 50418514333440. Its totient is φ = 7855917189120.

The previous prime is 21002121110099. The next prime is 21002121110197. The reversal of 21002121110120 is 2101112120012.

It is a super-2 number, since 2×21002121110120² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21002121110095 and 21002121110104.

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, 12935147 + ... + 14467973.

It is an arithmetic number, because the mean of its divisors is an integer number (393894643230).

Almost surely, 2^{21002121110120} is an apocalyptic number.

21002121110120 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 21002121110120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25209257166720).

21002121110120 is an abundant number, since it is smaller than the sum of its proper divisors (29416393223320).

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

21002121110120 is a wasteful number, since it uses less digits than its factorization.

21002121110120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1533195 (or 1533191 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21002121110120 its reverse (2101112120012), we get a palindrome (23103233230132).

The spelling of 21002121110120 in words is "twenty-one trillion, two billion, one hundred twenty-one million, one hundred ten thousand, one hundred twenty".