21822804865 has 4 divisors (see below), whose sum is σ = 26187365844. Its totient is φ = 17458243888.

The previous prime is 21822804841. The next prime is 21822804929. The reversal of 21822804865 is 56840822812.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3907250064 + 17915554801 = 62508^2 + 133849^2 .

It is a cyclic number.

It is not a de Polignac number, because 21822804865 - 2⁵ = 21822804833 is a prime.

It is a Duffinian 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, 2182280482 + ... + 2182280491.

It is an arithmetic number, because the mean of its divisors is an integer number (6546841461).

Almost surely, 2^21822804865 is an apocalyptic number.

It is an amenable number.

21822804865 is a deficient number, since it is larger than the sum of its proper divisors (4364560979).

21822804865 is an equidigital number, since it uses as much as digits as its factorization.

21822804865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4364560978.

The product of its (nonzero) digits is 491520, while the sum is 46.

The spelling of 21822804865 in words is "twenty-one billion, eight hundred twenty-two million, eight hundred four thousand, eight hundred sixty-five".