18734639 has 16 divisors (see below), whose sum is σ = 23452416. Its totient is φ = 14539200.

The previous prime is 18734603. The next prime is 18734641. The reversal of 18734639 is 93643781.

It is a cyclic number.

It is not a de Polignac number, because 18734639 - 2¹⁶ = 18669103 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18734596 and 18734605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18734039) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35699 + ... + 36219.

It is an arithmetic number, because the mean of its divisors is an integer number (1465776).

Almost surely, 2^18734639 is an apocalyptic number.

18734639 is a deficient number, since it is larger than the sum of its proper divisors (4717777).

18734639 is a wasteful number, since it uses less digits than its factorization.

18734639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1006.

The product of its digits is 108864, while the sum is 41.

The square root of 18734639 is about 4328.3529199916. The cubic root of 18734639 is about 265.5920735934.

The spelling of 18734639 in words is "eighteen million, seven hundred thirty-four thousand, six hundred thirty-nine".