21646635532 has 12 divisors (see below), whose sum is σ = 39187874880. Its totient is φ = 10450099856.

The previous prime is 21646635529. The next prime is 21646635539. The reversal of 21646635532 is 23553664612.

It is not an unprimeable number, because it can be changed into a prime (21646635539) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 93304348 + ... + 93304579.

It is an arithmetic number, because the mean of its divisors is an integer number (3265656240).

Almost surely, 2^21646635532 is an apocalyptic number.

It is an amenable number.

21646635532 is a deficient number, since it is larger than the sum of its proper divisors (17541239348).

21646635532 is a wasteful number, since it uses less digits than its factorization.

21646635532 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186608960 (or 186608958 counting only the distinct ones).

The product of its digits is 777600, while the sum is 43.

The spelling of 21646635532 in words is "twenty-one billion, six hundred forty-six million, six hundred thirty-five thousand, five hundred thirty-two".