21001300113221 has 4 divisors (see below), whose sum is σ = 21001373929452. Its totient is φ = 21001226296992.

The previous prime is 21001300113217. The next prime is 21001300113239. The reversal of 21001300113221 is 12231100310012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4756281192100 + 16245018921121 = 2180890^2 + 4030511^2 .

It is a cyclic number.

It is not a de Polignac number, because 21001300113221 - 2² = 21001300113217 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21001300113221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001300113821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36479696 + ... + 37050921.

It is an arithmetic number, because the mean of its divisors is an integer number (5250343482363).

Almost surely, 2^{21001300113221} is an apocalyptic number.

It is an amenable number.

21001300113221 is a deficient number, since it is larger than the sum of its proper divisors (73816231).

21001300113221 is an equidigital number, since it uses as much as digits as its factorization.

21001300113221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73816230.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 21001300113221 its reverse (12231100310012), we get a palindrome (33232400423233).

The spelling of 21001300113221 in words is "twenty-one trillion, one billion, three hundred million, one hundred thirteen thousand, two hundred twenty-one".