21021331213220 has 48 divisors (see below), whose sum is σ = 47541547369008. Its totient is φ = 7761559303680.

The previous prime is 21021331213187. The next prime is 21021331213247. The reversal of 21021331213220 is 2231213312012.

21021331213220 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 642751751524 + 20378579461696 = 801718^2 + 4514264^2 .

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, 11925230 + ... + 13574010.

It is an arithmetic number, because the mean of its divisors is an integer number (990448903521).

Almost surely, 2^{21021331213220} is an apocalyptic number.

21021331213220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21021331213220 is an abundant number, since it is smaller than the sum of its proper divisors (26520216155788).

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

21021331213220 is a wasteful number, since it uses less digits than its factorization.

21021331213220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1697840 (or 1697838 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

Adding to 21021331213220 its reverse (2231213312012), we get a palindrome (23252544525232).

The spelling of 21021331213220 in words is "twenty-one trillion, twenty-one billion, three hundred thirty-one million, two hundred thirteen thousand, two hundred twenty".