21321103220 has 12 divisors (see below), whose sum is σ = 44774316804. Its totient is φ = 8528441280.

The previous prime is 21321103091. The next prime is 21321103249. The reversal of 21321103220 is 2230112312.

It can be written as a sum of positive squares in 2 ways, for example, as 15601508836 + 5719594384 = 124906^2 + 75628^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 533027561 + ... + 533027600.

It is an arithmetic number, because the mean of its divisors is an integer number (3731193067).

Almost surely, 2^21321103220 is an apocalyptic number.

21321103220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21321103220 is an abundant number, since it is smaller than the sum of its proper divisors (23453213584).

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

21321103220 is a wasteful number, since it uses less digits than its factorization.

21321103220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1066055170 (or 1066055168 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21321103220 its reverse (2230112312), we get a palindrome (23551215532).

The spelling of 21321103220 in words is "twenty-one billion, three hundred twenty-one million, one hundred three thousand, two hundred twenty".