21664464404 has 12 divisors (see below), whose sum is σ = 41359432128. Its totient is φ = 9847483800.

The previous prime is 21664464401. The next prime is 21664464407. The reversal of 21664464404 is 40446446612.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21664464401) and next prime (21664464407).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21664464401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 246187052 + ... + 246187139.

It is an arithmetic number, because the mean of its divisors is an integer number (3446619344).

Almost surely, 2^21664464404 is an apocalyptic number.

It is an amenable number.

21664464404 is a deficient number, since it is larger than the sum of its proper divisors (19694967724).

21664464404 is a wasteful number, since it uses less digits than its factorization.

21664464404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 492374206 (or 492374204 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 41.

The spelling of 21664464404 in words is "twenty-one billion, six hundred sixty-four million, four hundred sixty-four thousand, four hundred four".