18681863 has 2 divisors, whose sum is σ = 18681864. Its totient is φ = 18681862.

The previous prime is 18681857. The next prime is 18681899. The reversal of 18681863 is 36818681.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18681863 - 2¹⁶ = 18616327 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18681863.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18681833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9340931 + 9340932.

It is an arithmetic number, because the mean of its divisors is an integer number (9340932).

Almost surely, 2^18681863 is an apocalyptic number.

18681863 is a deficient number, since it is larger than the sum of its proper divisors (1).

18681863 is an equidigital number, since it uses as much as digits as its factorization.

18681863 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 55296, while the sum is 41.

The square root of 18681863 is about 4322.2520750183. The cubic root of 18681863 is about 265.3424456200.

The spelling of 18681863 in words is "eighteen million, six hundred eighty-one thousand, eight hundred sixty-three".