18786643 has 2 divisors, whose sum is σ = 18786644. Its totient is φ = 18786642.

The previous prime is 18786637. The next prime is 18786661. The reversal of 18786643 is 34668781.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18786643 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18786643.

It is not a weakly prime, because it can be changed into another prime (18786613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9393321 + 9393322.

It is an arithmetic number, because the mean of its divisors is an integer number (9393322).

Almost surely, 2^18786643 is an apocalyptic number.

18786643 is a deficient number, since it is larger than the sum of its proper divisors (1).

18786643 is an equidigital number, since it uses as much as digits as its factorization.

18786643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 193536, while the sum is 43.

The square root of 18786643 is about 4334.3561228861. The cubic root of 18786643 is about 265.8375918929.

The spelling of 18786643 in words is "eighteen million, seven hundred eighty-six thousand, six hundred forty-three".