18993423 has 16 divisors (see below), whose sum is σ = 26804736. Its totient is φ = 11938080.

The previous prime is 18993419. The next prime is 18993427. The reversal of 18993423 is 32439981.

It is an interprime number because it is at equal distance from previous prime (18993419) and next prime (18993427).

It is not a de Polignac number, because 18993423 - 2² = 18993419 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18993427) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 2961 + ... + 6837.

It is an arithmetic number, because the mean of its divisors is an integer number (1675296).

Almost surely, 2^18993423 is an apocalyptic number.

18993423 is a deficient number, since it is larger than the sum of its proper divisors (7811313).

18993423 is a wasteful number, since it uses less digits than its factorization.

18993423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3974.

The product of its digits is 46656, while the sum is 39.

The square root of 18993423 is about 4358.1444446002. The cubic root of 18993423 is about 266.8093717089.

The spelling of 18993423 in words is "eighteen million, nine hundred ninety-three thousand, four hundred twenty-three".