18994663 has 2 divisors, whose sum is σ = 18994664. Its totient is φ = 18994662.

The previous prime is 18994643. The next prime is 18994687. The reversal of 18994663 is 36649981.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18994663 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18994643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9497331 + 9497332.

It is an arithmetic number, because the mean of its divisors is an integer number (9497332).

Almost surely, 2^18994663 is an apocalyptic number.

18994663 is a deficient number, since it is larger than the sum of its proper divisors (1).

18994663 is an equidigital number, since it uses as much as digits as its factorization.

18994663 is an evil number, because the sum of its binary digits is even.

The product of its digits is 279936, while the sum is 46.

The square root of 18994663 is about 4358.2867046582. The cubic root of 18994663 is about 266.8151778665.

The spelling of 18994663 in words is "eighteen million, nine hundred ninety-four thousand, six hundred sixty-three".