18728385 has 16 divisors (see below), whose sum is σ = 32270784. Its totient is φ = 9220032.

The previous prime is 18728363. The next prime is 18728393. The reversal of 18728385 is 58382781.

It is a happy number.

It is not a de Polignac number, because 18728385 - 2⁶ = 18728321 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47827 + ... + 48216.

It is an arithmetic number, because the mean of its divisors is an integer number (2016924).

Almost surely, 2^18728385 is an apocalyptic number.

18728385 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18728385 is a deficient number, since it is larger than the sum of its proper divisors (13542399).

18728385 is a wasteful number, since it uses less digits than its factorization.

18728385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96064.

The product of its digits is 107520, while the sum is 42.

The square root of 18728385 is about 4327.6304139795. The cubic root of 18728385 is about 265.5625169757.

The spelling of 18728385 in words is "eighteen million, seven hundred twenty-eight thousand, three hundred eighty-five".