21775564609 has 8 divisors (see below), whose sum is σ = 22462881728. Its totient is φ = 21098903760.

The previous prime is 21775564607. The next prime is 21775564687. The reversal of 21775564609 is 90646557712.

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

It is a cyclic number.

It is not a de Polignac number, because 21775564609 - 2¹ = 21775564607 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21775564607) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2659917 + ... + 2668090.

It is an arithmetic number, because the mean of its divisors is an integer number (2807860216).

Almost surely, 2^21775564609 is an apocalyptic number.

It is an amenable number.

21775564609 is a deficient number, since it is larger than the sum of its proper divisors (687317119).

21775564609 is an equidigital number, since it uses as much as digits as its factorization.

21775564609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5328135.

The product of its (nonzero) digits is 3175200, while the sum is 52.

The spelling of 21775564609 in words is "twenty-one billion, seven hundred seventy-five million, five hundred sixty-four thousand, six hundred nine".