21718806325 has 12 divisors (see below), whose sum is σ = 26934392160. Its totient is φ = 17373062960.

The previous prime is 21718806293. The next prime is 21718806337. The reversal of 21718806325 is 52360881712.

It is not a de Polignac number, because 21718806325 - 2⁵ = 21718806293 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 198282 + ... + 287668.

It is an arithmetic number, because the mean of its divisors is an integer number (2244532680).

Almost surely, 2^21718806325 is an apocalyptic number.

21718806325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21718806325 is a deficient number, since it is larger than the sum of its proper divisors (5215585835).

21718806325 is an equidigital number, since it uses as much as digits as its factorization.

21718806325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99116 (or 99111 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 43.

The spelling of 21718806325 in words is "twenty-one billion, seven hundred eighteen million, eight hundred six thousand, three hundred twenty-five".