18855885569 has 2 divisors, whose sum is σ = 18855885570. Its totient is φ = 18855885568.

The previous prime is 18855885541. The next prime is 18855885571. The reversal of 18855885569 is 96558855881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16820793025 + 2035092544 = 129695^2 + 45112^2 .

It is an emirp because it is prime and its reverse (96558855881) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18855885569 is a prime.

It is a super-2 number, since 2×18855885569² (a number of 21 digits) contains 22 as substring.

Together with 18855885571, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 18855885499 and 18855885508.

It is not a weakly prime, because it can be changed into another prime (18825885569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9427942784 + 9427942785.

It is an arithmetic number, because the mean of its divisors is an integer number (9427942785).

Almost surely, 2^18855885569 is an apocalyptic number.

It is an amenable number.

18855885569 is a deficient number, since it is larger than the sum of its proper divisors (1).

18855885569 is an equidigital number, since it uses as much as digits as its factorization.

18855885569 is an evil number, because the sum of its binary digits is even.

The product of its digits is 138240000, while the sum is 68.

The spelling of 18855885569 in words is "eighteen billion, eight hundred fifty-five million, eight hundred eighty-five thousand, five hundred sixty-nine".