18799991 has 8 divisors (see below), whose sum is σ = 21512064. Its totient is φ = 16094520.

The previous prime is 18799967. The next prime is 18799997. The reversal of 18799991 is 19999781.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18799991 - 2¹⁴ = 18783607 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18799997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9476 + ... + 11286.

It is an arithmetic number, because the mean of its divisors is an integer number (2689008).

Almost surely, 2^18799991 is an apocalyptic number.

18799991 is a deficient number, since it is larger than the sum of its proper divisors (2712073).

18799991 is a wasteful number, since it uses less digits than its factorization.

18799991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3301.

The product of its digits is 367416, while the sum is 53.

The square root of 18799991 is about 4335.8956398880. The cubic root of 18799991 is about 265.9005366160.

The spelling of 18799991 in words is "eighteen million, seven hundred ninety-nine thousand, nine hundred ninety-one".