21331320211220 has 24 divisors (see below), whose sum is σ = 44796288529608. Its totient is φ = 8532429782400.

The previous prime is 21331320211189. The next prime is 21331320211247. The reversal of 21331320211220 is 2211202313312.

It can be written as a sum of positive squares in 4 ways, for example, as 1130232639376 + 20201087571844 = 1063124^2 + 4494562^2 .

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, 4351751 + ... + 7848590.

It is an arithmetic number, because the mean of its divisors is an integer number (1866512022067).

Almost surely, 2^{21331320211220} is an apocalyptic number.

21331320211220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21331320211220 is an abundant number, since it is smaller than the sum of its proper divisors (23464968318388).

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

21331320211220 is a wasteful number, since it uses less digits than its factorization.

21331320211220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12287771 (or 12287769 counting only the distinct ones).

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

Adding to 21331320211220 its reverse (2211202313312), we get a palindrome (23542522524532).

The spelling of 21331320211220 in words is "twenty-one trillion, three hundred thirty-one billion, three hundred twenty million, two hundred eleven thousand, two hundred twenty".