21516664005 has 24 divisors (see below), whose sum is σ = 38162892768. Its totient is φ = 11208679776.

The previous prime is 21516663991. The next prime is 21516664007. The reversal of 21516664005 is 50046661512.

It is not a de Polignac number, because 21516664005 - 2²⁵ = 21483109573 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21516664007) 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 23 ways as a sum of consecutive naturals, for example, 5557927 + ... + 5561796.

It is an arithmetic number, because the mean of its divisors is an integer number (1590120532).

Almost surely, 2^21516664005 is an apocalyptic number.

It is an amenable number.

21516664005 is a deficient number, since it is larger than the sum of its proper divisors (16646228763).

21516664005 is a wasteful number, since it uses less digits than its factorization.

21516664005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11119777 (or 11119774 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The spelling of 21516664005 in words is "twenty-one billion, five hundred sixteen million, six hundred sixty-four thousand, five".