18589993 has 4 divisors (see below), whose sum is σ = 19683540. Its totient is φ = 17496448.

The previous prime is 18589979. The next prime is 18589997. The reversal of 18589993 is 39998581.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 39998581 = 7 ⋅5714083.

It can be written as a sum of positive squares in 2 ways, for example, as 7118224 + 11471769 = 2668^2 + 3387^2 .

It is a cyclic number.

It is not a de Polignac number, because 18589993 - 2⁹ = 18589481 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18589993.

It is not an unprimeable number, because it can be changed into a prime (18589997) 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, 546748 + ... + 546781.

It is an arithmetic number, because the mean of its divisors is an integer number (4920885).

Almost surely, 2^18589993 is an apocalyptic number.

It is an amenable number.

18589993 is a deficient number, since it is larger than the sum of its proper divisors (1093547).

18589993 is a wasteful number, since it uses less digits than its factorization.

18589993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1093546.

The product of its digits is 699840, while the sum is 52.

The square root of 18589993 is about 4311.6114157006. The cubic root of 18589993 is about 264.9067810250.

The spelling of 18589993 in words is "eighteen million, five hundred eighty-nine thousand, nine hundred ninety-three".