21120002120 has 64 divisors (see below), whose sum is σ = 55571598720. Its totient is φ = 7072740864.

The previous prime is 21120002117. The next prime is 21120002179. The reversal of 21120002120 is 2120002112.

It is a happy 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, 865037 + ... + 889116.

It is an arithmetic number, because the mean of its divisors is an integer number (868306230).

Almost surely, 2^21120002120 is an apocalyptic number.

21120002120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21120002120 is an abundant number, since it is smaller than the sum of its proper divisors (34451596600).

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

21120002120 is a wasteful number, since it uses less digits than its factorization.

21120002120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1754214 (or 1754210 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21120002120 its reverse (2120002112), we get a palindrome (23240004232).

The spelling of 21120002120 in words is "twenty-one billion, one hundred twenty million, two thousand, one hundred twenty".