21544041313 has 4 divisors (see below), whose sum is σ = 21567691008. Its totient is φ = 21520391620.

The previous prime is 21544041293. The next prime is 21544041359. The reversal of 21544041313 is 31314044512.

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 a de Polignac number, because none of the positive numbers 2^k-21544041313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21548041313) 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, 11823481 + ... + 11825302.

It is an arithmetic number, because the mean of its divisors is an integer number (5391922752).

Almost surely, 2^21544041313 is an apocalyptic number.

It is an amenable number.

21544041313 is a deficient number, since it is larger than the sum of its proper divisors (23649695).

21544041313 is an equidigital number, since it uses as much as digits as its factorization.

21544041313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23649694.

The product of its (nonzero) digits is 5760, while the sum is 28.

Adding to 21544041313 its reverse (31314044512), we get a palindrome (52858085825).

The spelling of 21544041313 in words is "twenty-one billion, five hundred forty-four million, forty-one thousand, three hundred thirteen".