21566612045 has 8 divisors (see below), whose sum is σ = 28232655840. Its totient is φ = 15684808720.

The previous prime is 21566612003. The next prime is 21566612057. The reversal of 21566612045 is 54021666512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21566612045 - 2²⁴ = 21549834829 is a prime.

It is a congruent number.

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, 196060055 + ... + 196060164.

It is an arithmetic number, because the mean of its divisors is an integer number (3529081980).

Almost surely, 2^21566612045 is an apocalyptic number.

It is an amenable number.

21566612045 is a deficient number, since it is larger than the sum of its proper divisors (6666043795).

21566612045 is a wasteful number, since it uses less digits than its factorization.

21566612045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 392120235.

The product of its (nonzero) digits is 86400, while the sum is 38.

The spelling of 21566612045 in words is "twenty-one billion, five hundred sixty-six million, six hundred twelve thousand, forty-five".