21466665924 has 24 divisors (see below), whose sum is σ = 54642422688. Its totient is φ = 6505050240.

The previous prime is 21466665917. The next prime is 21466665929. The reversal of 21466665924 is 42956666412.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21466665929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81312997 + ... + 81313260.

It is an arithmetic number, because the mean of its divisors is an integer number (2276767612).

Almost surely, 2^21466665924 is an apocalyptic number.

It is an amenable number.

21466665924 is an abundant number, since it is smaller than the sum of its proper divisors (33175756764).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21466665924 is a wasteful number, since it uses less digits than its factorization.

21466665924 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162626275 (or 162626273 counting only the distinct ones).

The product of its digits is 3732480, while the sum is 51.

The spelling of 21466665924 in words is "twenty-one billion, four hundred sixty-six million, six hundred sixty-five thousand, nine hundred twenty-four".