21975722659 has 4 divisors (see below), whose sum is σ = 23973515640. Its totient is φ = 19977929680.

The previous prime is 21975722641. The next prime is 21975722663. The reversal of 21975722659 is 95622757912.

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

It is a cyclic number.

It is not a de Polignac number, because 21975722659 - 2¹⁵ = 21975689891 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21975722759) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 998896474 + ... + 998896495.

It is an arithmetic number, because the mean of its divisors is an integer number (5993378910).

Almost surely, 2^21975722659 is an apocalyptic number.

21975722659 is a deficient number, since it is larger than the sum of its proper divisors (1997792981).

21975722659 is a wasteful number, since it uses less digits than its factorization.

21975722659 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1997792980.

The product of its digits is 4762800, while the sum is 55.

The spelling of 21975722659 in words is "twenty-one billion, nine hundred seventy-five million, seven hundred twenty-two thousand, six hundred fifty-nine".