21044313551321 has 4 divisors (see below), whose sum is σ = 21044741269632. Its totient is φ = 21043885833012.

The previous prime is 21044313551299. The next prime is 21044313551353. The reversal of 21044313551321 is 12315531344012.

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 21044313551321 - 2⁶ = 21044313551257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21044613551321) 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, 213785345 + ... + 213883758.

It is an arithmetic number, because the mean of its divisors is an integer number (5261185317408).

Almost surely, 2^{21044313551321} is an apocalyptic number.

It is an amenable number.

21044313551321 is a deficient number, since it is larger than the sum of its proper divisors (427718311).

21044313551321 is an equidigital number, since it uses as much as digits as its factorization.

21044313551321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 427718310.

The product of its (nonzero) digits is 43200, while the sum is 35.

Adding to 21044313551321 its reverse (12315531344012), we get a palindrome (33359844895333).

The spelling of 21044313551321 in words is "twenty-one trillion, forty-four billion, three hundred thirteen million, five hundred fifty-one thousand, three hundred twenty-one".