21604425875 has 8 divisors (see below), whose sum is σ = 26962323648. Its totient is φ = 17283540600.

The previous prime is 21604425823. The next prime is 21604425923. The reversal of 21604425875 is 57852440612.

It is not a de Polignac number, because 21604425875 - 2²² = 21600231571 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 86417579 + ... + 86417828.

It is an arithmetic number, because the mean of its divisors is an integer number (3370290456).

Almost surely, 2^21604425875 is an apocalyptic number.

21604425875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21604425875 is a deficient number, since it is larger than the sum of its proper divisors (5357897773).

21604425875 is an equidigital number, since it uses as much as digits as its factorization.

21604425875 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172835422 (or 172835412 counting only the distinct ones).

The product of its (nonzero) digits is 537600, while the sum is 44.

The spelling of 21604425875 in words is "twenty-one billion, six hundred four million, four hundred twenty-five thousand, eight hundred seventy-five".