18691728 has 40 divisors (see below), whose sum is σ = 52678176. Its totient is φ = 5664000.

The previous prime is 18691711. The next prime is 18691741. The reversal of 18691728 is 82719681.

It is a self number, because there is not a number n which added to its sum of digits gives 18691728.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17173 + ... + 18228.

Almost surely, 2^18691728 is an apocalyptic number.

It is an amenable number.

18691728 is an abundant number, since it is smaller than the sum of its proper divisors (33986448).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18691728 is a wasteful number, since it uses less digits than its factorization.

18691728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35423 (or 35417 counting only the distinct ones).

The product of its digits is 48384, while the sum is 42.

The square root of 18691728 is about 4323.3931118972. The cubic root of 18691728 is about 265.3891422943.

The spelling of 18691728 in words is "eighteen million, six hundred ninety-one thousand, seven hundred twenty-eight".