18638943 has 8 divisors (see below), whose sum is σ = 26160000. Its totient is φ = 11771928.

The previous prime is 18638923. The next prime is 18638957. The reversal of 18638943 is 34983681.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18638943 - 2⁵ = 18638911 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18638895 and 18638904.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18638923) 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 7 ways as a sum of consecutive naturals, for example, 163443 + ... + 163556.

It is an arithmetic number, because the mean of its divisors is an integer number (3270000).

Almost surely, 2^18638943 is an apocalyptic number.

18638943 is a deficient number, since it is larger than the sum of its proper divisors (7521057).

18638943 is a wasteful number, since it uses less digits than its factorization.

18638943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327021.

The product of its digits is 124416, while the sum is 42.

The square root of 18638943 is about 4317.2842158005. The cubic root of 18638943 is about 265.1390892009.

The spelling of 18638943 in words is "eighteen million, six hundred thirty-eight thousand, nine hundred forty-three".