21566098808 has 16 divisors (see below), whose sum is σ = 42564669000. Its totient is φ = 10215520416.

The previous prime is 21566098793. The next prime is 21566098811. The reversal of 21566098808 is 80889066512.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 21566098808.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70940963 + ... + 70941266.

Almost surely, 2^21566098808 is an apocalyptic number.

It is an amenable number.

21566098808 is a deficient number, since it is larger than the sum of its proper divisors (20998570192).

21566098808 is a wasteful number, since it uses less digits than its factorization.

21566098808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141882254 (or 141882250 counting only the distinct ones).

The product of its (nonzero) digits is 1658880, while the sum is 53.

The spelling of 21566098808 in words is "twenty-one billion, five hundred sixty-six million, ninety-eight thousand, eight hundred eight".