21648642875 has 8 divisors (see below), whose sum is σ = 27017506464. Its totient is φ = 17318914200.

The previous prime is 21648642863. The next prime is 21648642923. The reversal of 21648642875 is 57824684612.

It is not a de Polignac number, because 21648642875 - 2⁶ = 21648642811 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, 86594447 + ... + 86594696.

It is an arithmetic number, because the mean of its divisors is an integer number (3377188308).

Almost surely, 2^21648642875 is an apocalyptic number.

21648642875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21648642875 is a deficient number, since it is larger than the sum of its proper divisors (5368863589).

21648642875 is an equidigital number, since it uses as much as digits as its factorization.

21648642875 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173189158 (or 173189148 counting only the distinct ones).

The product of its digits is 5160960, while the sum is 53.

The spelling of 21648642875 in words is "twenty-one billion, six hundred forty-eight million, six hundred forty-two thousand, eight hundred seventy-five".