18638863 has 2 divisors, whose sum is σ = 18638864. Its totient is φ = 18638862.

The previous prime is 18638839. The next prime is 18638897. The reversal of 18638863 is 36883681.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18638863 - 2¹⁷ = 18507791 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18638803) 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, 9319431 + 9319432.

It is an arithmetic number, because the mean of its divisors is an integer number (9319432).

Almost surely, 2^18638863 is an apocalyptic number.

18638863 is a deficient number, since it is larger than the sum of its proper divisors (1).

18638863 is an equidigital number, since it uses as much as digits as its factorization.

18638863 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 165888, while the sum is 43.

The square root of 18638863 is about 4317.2749507068. The cubic root of 18638863 is about 265.1387098668.

The spelling of 18638863 in words is "eighteen million, six hundred thirty-eight thousand, eight hundred sixty-three".