18663899 has 2 divisors, whose sum is σ = 18663900. Its totient is φ = 18663898.

The previous prime is 18663893. The next prime is 18663913. The reversal of 18663899 is 99836681.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18663899 is a prime.

It is a super-2 number, since 2×18663899² = 696682251764402, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18663893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9331949 + 9331950.

It is an arithmetic number, because the mean of its divisors is an integer number (9331950).

Almost surely, 2^18663899 is an apocalyptic number.

18663899 is a deficient number, since it is larger than the sum of its proper divisors (1).

18663899 is an equidigital number, since it uses as much as digits as its factorization.

18663899 is an evil number, because the sum of its binary digits is even.

The product of its digits is 559872, while the sum is 50.

The square root of 18663899 is about 4320.1734918866. The cubic root of 18663899 is about 265.2573695165.

The spelling of 18663899 in words is "eighteen million, six hundred sixty-three thousand, eight hundred ninety-nine".