18989863 has 2 divisors, whose sum is σ = 18989864. Its totient is φ = 18989862.

The previous prime is 18989857. The next prime is 18989879. The reversal of 18989863 is 36898981.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18989863 - 2⁹ = 18989351 is a prime.

It is a super-2 number, since 2×18989863² = 721229793517538, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 18989863.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18983863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9494931 + 9494932.

It is an arithmetic number, because the mean of its divisors is an integer number (9494932).

Almost surely, 2^18989863 is an apocalyptic number.

18989863 is a deficient number, since it is larger than the sum of its proper divisors (1).

18989863 is an equidigital number, since it uses as much as digits as its factorization.

18989863 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 746496, while the sum is 52.

The square root of 18989863 is about 4357.7359947569. The cubic root of 18989863 is about 266.7927010134.

The spelling of 18989863 in words is "eighteen million, nine hundred eighty-nine thousand, eight hundred sixty-three".