21059495013 has 4 divisors (see below), whose sum is σ = 28079326688. Its totient is φ = 14039663340.

The previous prime is 21059495011. The next prime is 21059495021. The reversal of 21059495013 is 31059495012.

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 not a de Polignac number, because 21059495013 - 2¹ = 21059495011 is a prime.

It is a super-3 number, since 3×21059495013³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21059495011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3509915833 + ... + 3509915838.

It is an arithmetic number, because the mean of its divisors is an integer number (7019831672).

Almost surely, 2^21059495013 is an apocalyptic number.

It is an amenable number.

21059495013 is a deficient number, since it is larger than the sum of its proper divisors (7019831675).

21059495013 is an equidigital number, since it uses as much as digits as its factorization.

21059495013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7019831674.

The product of its (nonzero) digits is 48600, while the sum is 39.

Subtracting 21059495013 from its reverse (31059495012), we obtain a palindrome (9999999999).

The spelling of 21059495013 in words is "twenty-one billion, fifty-nine million, four hundred ninety-five thousand, thirteen".