18739663 has 2 divisors, whose sum is σ = 18739664. Its totient is φ = 18739662.

The previous prime is 18739619. The next prime is 18739667. The reversal of 18739663 is 36693781.

It is a strong prime.

It is an emirp because it is prime and its reverse (36693781) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18739663 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18739667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9369831 + 9369832.

It is an arithmetic number, because the mean of its divisors is an integer number (9369832).

Almost surely, 2^18739663 is an apocalyptic number.

18739663 is a deficient number, since it is larger than the sum of its proper divisors (1).

18739663 is an equidigital number, since it uses as much as digits as its factorization.

18739663 is an evil number, because the sum of its binary digits is even.

The product of its digits is 163296, while the sum is 43.

The square root of 18739663 is about 4328.9332404185. The cubic root of 18739663 is about 265.6158124250.

The spelling of 18739663 in words is "eighteen million, seven hundred thirty-nine thousand, six hundred sixty-three".