21204115402120 has 128 divisors (see below), whose sum is σ = 56625620198400. Its totient is φ = 6994929021696.

The previous prime is 21204115402081. The next prime is 21204115402157. The reversal of 21204115402120 is 2120451140212.

It is a super-2 number, since 2×21204115402120² (a number of 27 digits) contains 22 as substring.

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, 12336150 + ... + 13949509.

It is an arithmetic number, because the mean of its divisors is an integer number (442387657800).

Almost surely, 2^{21204115402120} is an apocalyptic number.

21204115402120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21204115402120 is an abundant number, since it is smaller than the sum of its proper divisors (35421504796280).

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

21204115402120 is a wasteful number, since it uses less digits than its factorization.

21204115402120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26285787 (or 26285783 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 25.

Adding to 21204115402120 its reverse (2120451140212), we get a palindrome (23324566542332).

The spelling of 21204115402120 in words is "twenty-one trillion, two hundred four billion, one hundred fifteen million, four hundred two thousand, one hundred twenty".