18438671 has 4 divisors (see below), whose sum is σ = 18447312. Its totient is φ = 18430032.

The previous prime is 18438649. The next prime is 18438689. The reversal of 18438671 is 17683481.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 18438671 - 2¹⁰ = 18437647 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18434671) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1451 + ... + 6243.

It is an arithmetic number, because the mean of its divisors is an integer number (4611828).

Almost surely, 2^18438671 is an apocalyptic number.

18438671 is a deficient number, since it is larger than the sum of its proper divisors (8641).

18438671 is an equidigital number, since it uses as much as digits as its factorization.

18438671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8640.

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

The square root of 18438671 is about 4294.0273636762. The cubic root of 18438671 is about 264.1860440606.

The spelling of 18438671 in words is "eighteen million, four hundred thirty-eight thousand, six hundred seventy-one".