21666124652 has 24 divisors (see below), whose sum is σ = 38805808272. Its totient is φ = 10578859200.

The previous prime is 21666124639. The next prime is 21666124673. The reversal of 21666124652 is 25642166612.

It is a super-2 number, since 2×21666124652² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1018202 + ... + 1039262.

It is an arithmetic number, because the mean of its divisors is an integer number (1616908678).

Almost surely, 2^21666124652 is an apocalyptic number.

It is an amenable number.

21666124652 is a deficient number, since it is larger than the sum of its proper divisors (17139683620).

21666124652 is a wasteful number, since it uses less digits than its factorization.

21666124652 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27089 (or 27087 counting only the distinct ones).

The product of its digits is 207360, while the sum is 41.

The spelling of 21666124652 in words is "twenty-one billion, six hundred sixty-six million, one hundred twenty-four thousand, six hundred fifty-two".