21373664756105 has 4 divisors (see below), whose sum is σ = 25648397707332. Its totient is φ = 17098931804880.

The previous prime is 21373664756071. The next prime is 21373664756117. The reversal of 21373664756105 is 50165746637312.

21373664756105 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

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 13329333676096 + 8044331080009 = 3650936^2 + 2836253^2 .

It is not a de Polignac number, because 21373664756105 - 2¹⁶ = 21373664690569 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2137366475606 + ... + 2137366475615.

It is an arithmetic number, because the mean of its divisors is an integer number (6412099426833).

Almost surely, 2^{21373664756105} is an apocalyptic number.

It is an amenable number.

21373664756105 is a deficient number, since it is larger than the sum of its proper divisors (4274732951227).

21373664756105 is an equidigital number, since it uses as much as digits as its factorization.

21373664756105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4274732951226.

The product of its (nonzero) digits is 19051200, while the sum is 56.

The spelling of 21373664756105 in words is "twenty-one trillion, three hundred seventy-three billion, six hundred sixty-four million, seven hundred fifty-six thousand, one hundred five".