21001321111013 has 4 divisors (see below), whose sum is σ = 21678783082368. Its totient is φ = 20323859139660.

The previous prime is 21001321110997. The next prime is 21001321111021. The reversal of 21001321111013 is 31011112310012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21001321111013 - 2⁴ = 21001321110997 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21001321110982 and 21001321111000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001321111073) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 338730985631 + ... + 338730985692.

It is an arithmetic number, because the mean of its divisors is an integer number (5419695770592).

Almost surely, 2^{21001321111013} is an apocalyptic number.

It is an amenable number.

21001321111013 is a deficient number, since it is larger than the sum of its proper divisors (677461971355).

21001321111013 is an equidigital number, since it uses as much as digits as its factorization.

21001321111013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 677461971354.

The product of its (nonzero) digits is 36, while the sum is 17.

Adding to 21001321111013 its reverse (31011112310012), we get a palindrome (52012433421025).

The spelling of 21001321111013 in words is "twenty-one trillion, one billion, three hundred twenty-one million, one hundred eleven thousand, thirteen".