21604614621 has 8 divisors (see below), whose sum is σ = 28836574944. Its totient is φ = 14387865360.

The previous prime is 21604614583. The next prime is 21604614623. The reversal of 21604614621 is 12641640612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-21604614621 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21604614623) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3799450 + ... + 3805131.

It is an arithmetic number, because the mean of its divisors is an integer number (3604571868).

Almost surely, 2^21604614621 is an apocalyptic number.

It is an amenable number.

21604614621 is a deficient number, since it is larger than the sum of its proper divisors (7231960323).

21604614621 is an equidigital number, since it uses as much as digits as its factorization.

21604614621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7605531.

The product of its (nonzero) digits is 13824, while the sum is 33.

The spelling of 21604614621 in words is "twenty-one billion, six hundred four million, six hundred fourteen thousand, six hundred twenty-one".