21604609401 has 8 divisors (see below), whose sum is σ = 28837157280. Its totient is φ = 14387567232.

The previous prime is 21604609381. The next prime is 21604609421. The reversal of 21604609401 is 10490640612.

It is an interprime number because it is at equal distance from previous prime (21604609381) and next prime (21604609421).

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

It is not a de Polignac number, because 21604609401 - 2⁶ = 21604609337 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21604609421) 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 7 ways as a sum of consecutive naturals, for example, 3873175 + ... + 3878748.

It is an arithmetic number, because the mean of its divisors is an integer number (3604644660).

Almost surely, 2^21604609401 is an apocalyptic number.

It is an amenable number.

21604609401 is a deficient number, since it is larger than the sum of its proper divisors (7232547879).

21604609401 is an equidigital number, since it uses as much as digits as its factorization.

21604609401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7752855.

The product of its (nonzero) digits is 10368, while the sum is 33.

The spelling of 21604609401 in words is "twenty-one billion, six hundred four million, six hundred nine thousand, four hundred one".