21204103220 has 24 divisors (see below), whose sum is σ = 45283341600. Its totient is φ = 8337884192.

The previous prime is 21204103187. The next prime is 21204103231. The reversal of 21204103220 is 2230140212.

It is a super-2 number, since 2×21204103220² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8983610 + ... + 8985969.

It is an arithmetic number, because the mean of its divisors is an integer number (1886805900).

Almost surely, 2^21204103220 is an apocalyptic number.

21204103220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21204103220 is an abundant number, since it is smaller than the sum of its proper divisors (24079238380).

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

21204103220 is a wasteful number, since it uses less digits than its factorization.

21204103220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17969647 (or 17969645 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

Adding to 21204103220 its reverse (2230140212), we get a palindrome (23434243432).

The spelling of 21204103220 in words is "twenty-one billion, two hundred four million, one hundred three thousand, two hundred twenty".