21715617747325 has 6 divisors (see below), whose sum is σ = 26927366006714. Its totient is φ = 17372494197840.

The previous prime is 21715617747323. The next prime is 21715617747413. The reversal of 21715617747325 is 52374771651712.

It can be written as a sum of positive squares in 3 ways, for example, as 28592780836 + 21687024966489 = 169094^2 + 4656933^2 .

It is not a de Polignac number, because 21715617747325 - 2¹ = 21715617747323 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21715617747325.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21715617747323) 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 5 ways as a sum of consecutive naturals, for example, 434312354922 + ... + 434312354971.

Almost surely, 2^{21715617747325} is an apocalyptic number.

21715617747325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21715617747325 is a deficient number, since it is larger than the sum of its proper divisors (5211748259389).

21715617747325 is an equidigital number, since it uses as much as digits as its factorization.

21715617747325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 868624709903 (or 868624709898 counting only the distinct ones).

The product of its digits is 17287200, while the sum is 58.

The spelling of 21715617747325 in words is "twenty-one trillion, seven hundred fifteen billion, six hundred seventeen million, seven hundred forty-seven thousand, three hundred twenty-five".