21001311233220 has 24 divisors (see below), whose sum is σ = 58803671453184. Its totient is φ = 5600349662176.

The previous prime is 21001311233207. The next prime is 21001311233251. The reversal of 21001311233220 is 2233211310012.

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, 175010926884 + ... + 175010927003.

It is an arithmetic number, because the mean of its divisors is an integer number (2450152977216).

Almost surely, 2^{21001311233220} is an apocalyptic number.

21001311233220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001311233220 is an abundant number, since it is smaller than the sum of its proper divisors (37802360219964).

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

21001311233220 is a wasteful number, since it uses less digits than its factorization.

21001311233220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 350021853899 (or 350021853897 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

Adding to 21001311233220 its reverse (2233211310012), we get a palindrome (23234522543232).

The spelling of 21001311233220 in words is "twenty-one trillion, one billion, three hundred eleven million, two hundred thirty-three thousand, two hundred twenty".