21608548865 has 16 divisors (see below), whose sum is σ = 26529242880. Its totient is φ = 16892029440.

The previous prime is 21608548799. The next prime is 21608548867. The reversal of 21608548865 is 56884580612.

It is not a de Polignac number, because 21608548865 - 2¹⁰ = 21608547841 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21608548867) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 243671 + ... + 320300.

It is an arithmetic number, because the mean of its divisors is an integer number (1658077680).

Almost surely, 2^21608548865 is an apocalyptic number.

It is an amenable number.

21608548865 is a deficient number, since it is larger than the sum of its proper divisors (4920694015).

21608548865 is an equidigital number, since it uses as much as digits as its factorization.

21608548865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 564152.

The product of its (nonzero) digits is 3686400, while the sum is 53.

The spelling of 21608548865 in words is "twenty-one billion, six hundred eight million, five hundred forty-eight thousand, eight hundred sixty-five".