18318647 has 4 divisors (see below), whose sum is σ = 18458616. Its totient is φ = 18178680.

The previous prime is 18318623. The next prime is 18318659. The reversal of 18318647 is 74681381.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18318647 - 2⁶ = 18318583 is a prime.

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 18318647.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18318617) 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, 69788 + ... + 70049.

It is an arithmetic number, because the mean of its divisors is an integer number (4614654).

Almost surely, 2^18318647 is an apocalyptic number.

18318647 is a deficient number, since it is larger than the sum of its proper divisors (139969).

18318647 is a wasteful number, since it uses less digits than its factorization.

18318647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139968.

The product of its digits is 32256, while the sum is 38.

The square root of 18318647 is about 4280.0288550429. The cubic root of 18318647 is about 263.6115681541.

The spelling of 18318647 in words is "eighteen million, three hundred eighteen thousand, six hundred forty-seven".