18663907 has 4 divisors (see below), whose sum is σ = 19307520. Its totient is φ = 18020296.

The previous prime is 18663899. The next prime is 18663913. The reversal of 18663907 is 70936681.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 70936681 = 1361 ⋅52121.

It is a cyclic number.

It is not a de Polignac number, because 18663907 - 2³ = 18663899 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18663907.

It is not an unprimeable number, because it can be changed into a prime (18663917) 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 in 3 ways as a sum of consecutive naturals, for example, 321763 + ... + 321820.

It is an arithmetic number, because the mean of its divisors is an integer number (4826880).

Almost surely, 2^18663907 is an apocalyptic number.

18663907 is a deficient number, since it is larger than the sum of its proper divisors (643613).

18663907 is an equidigital number, since it uses as much as digits as its factorization.

18663907 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 643612.

The product of its (nonzero) digits is 54432, while the sum is 40.

The square root of 18663907 is about 4320.1744177753. The cubic root of 18663907 is about 265.2574074160.

The spelling of 18663907 in words is "eighteen million, six hundred sixty-three thousand, nine hundred seven".