22517972821 has 2 divisors, whose sum is σ = 22517972822. Its totient is φ = 22517972820.

The previous prime is 22517972819. The next prime is 22517972843. The reversal of 22517972821 is 12827971522.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22425062500 + 92910321 = 149750^2 + 9639^2 .

It is a cyclic number.

It is not a de Polignac number, because 22517972821 - 2¹ = 22517972819 is a prime.

Together with 22517972819, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22517972621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11258986410 + 11258986411.

It is an arithmetic number, because the mean of its divisors is an integer number (11258986411).

Almost surely, 2^22517972821 is an apocalyptic number.

It is an amenable number.

22517972821 is a deficient number, since it is larger than the sum of its proper divisors (1).

22517972821 is an equidigital number, since it uses as much as digits as its factorization.

22517972821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 282240, while the sum is 46.

The spelling of 22517972821 in words is "twenty-two billion, five hundred seventeen million, nine hundred seventy-two thousand, eight hundred twenty-one".