18166663 has 2 divisors, whose sum is σ = 18166664. Its totient is φ = 18166662.

The previous prime is 18166661. The next prime is 18166669. The reversal of 18166663 is 36666181.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18166663 - 2¹ = 18166661 is a prime.

Together with 18166661, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18166661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9083331 + 9083332.

It is an arithmetic number, because the mean of its divisors is an integer number (9083332).

Almost surely, 2^18166663 is an apocalyptic number.

18166663 is a deficient number, since it is larger than the sum of its proper divisors (1).

18166663 is an equidigital number, since it uses as much as digits as its factorization.

18166663 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 37.

The square root of 18166663 is about 4262.2368540474. The cubic root of 18166663 is about 262.8805087840.

The spelling of 18166663 in words is "eighteen million, one hundred sixty-six thousand, six hundred sixty-three".