18440663 has 2 divisors, whose sum is σ = 18440664. Its totient is φ = 18440662.

The previous prime is 18440651. The next prime is 18440671. The reversal of 18440663 is 36604481.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18440663 - 2⁴ = 18440647 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18440623) 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, 9220331 + 9220332.

It is an arithmetic number, because the mean of its divisors is an integer number (9220332).

Almost surely, 2^18440663 is an apocalyptic number.

18440663 is a deficient number, since it is larger than the sum of its proper divisors (1).

18440663 is an equidigital number, since it uses as much as digits as its factorization.

18440663 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13824, while the sum is 32.

The square root of 18440663 is about 4294.2593074941. The cubic root of 18440663 is about 264.1955573936.

The spelling of 18440663 in words is "eighteen million, four hundred forty thousand, six hundred sixty-three".