18363889 has 2 divisors, whose sum is σ = 18363890. Its totient is φ = 18363888.

The previous prime is 18363883. The next prime is 18363911. The reversal of 18363889 is 98836381.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17363889 + 1000000 = 4167^2 + 1000^2 .

It is a cyclic number.

It is not a de Polignac number, because 18363889 - 2⁵ = 18363857 is a prime.

It is not a weakly prime, because it can be changed into another prime (18363883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9181944 + 9181945.

It is an arithmetic number, because the mean of its divisors is an integer number (9181945).

Almost surely, 2^18363889 is an apocalyptic number.

It is an amenable number.

18363889 is a deficient number, since it is larger than the sum of its proper divisors (1).

18363889 is an equidigital number, since it uses as much as digits as its factorization.

18363889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 248832, while the sum is 46.

The square root of 18363889 is about 4285.3108405342. The cubic root of 18363889 is about 263.8284056709.

The spelling of 18363889 in words is "eighteen million, three hundred sixty-three thousand, eight hundred eighty-nine".