18216144889 has 2 divisors, whose sum is σ = 18216144890. Its totient is φ = 18216144888.

The previous prime is 18216144847. The next prime is 18216144907. The reversal of 18216144889 is 98844161281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11301390864 + 6914754025 = 106308^2 + 83155^2 .

It is a cyclic number.

It is not a de Polignac number, because 18216144889 - 2¹⁷ = 18216013817 is a prime.

It is not a weakly prime, because it can be changed into another prime (18216144829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9108072444 + 9108072445.

It is an arithmetic number, because the mean of its divisors is an integer number (9108072445).

Almost surely, 2^18216144889 is an apocalyptic number.

It is an amenable number.

18216144889 is a deficient number, since it is larger than the sum of its proper divisors (1).

18216144889 is an equidigital number, since it uses as much as digits as its factorization.

18216144889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 884736, while the sum is 52.

The spelling of 18216144889 in words is "eighteen billion, two hundred sixteen million, one hundred forty-four thousand, eight hundred eighty-nine".