21664969153 has 16 divisors (see below), whose sum is σ = 22150656000. Its totient is φ = 21183582672.

The previous prime is 21664969147. The next prime is 21664969189. The reversal of 21664969153 is 35196946612.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21664969153 - 2³³ = 13075034561 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21664969153.

It is not an unprimeable number, because it can be changed into a prime (21664469153) 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, 9815376 + ... + 9817582.

It is an arithmetic number, because the mean of its divisors is an integer number (1384416000).

Almost surely, 2^21664969153 is an apocalyptic number.

It is an amenable number.

21664969153 is a deficient number, since it is larger than the sum of its proper divisors (485686847).

21664969153 is a wasteful number, since it uses less digits than its factorization.

21664969153 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3084.

The product of its digits is 2099520, while the sum is 52.

The spelling of 21664969153 in words is "twenty-one billion, six hundred sixty-four million, nine hundred sixty-nine thousand, one hundred fifty-three".