18423998 has 4 divisors (see below), whose sum is σ = 27636000. Its totient is φ = 9211998.

The previous prime is 18423967. The next prime is 18424027. The reversal of 18423998 is 89932481.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a Curzon number.

It is a congruent number.

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 as a sum of consecutive naturals, namely, 4605998 + ... + 4606001.

It is an arithmetic number, because the mean of its divisors is an integer number (6909000).

Almost surely, 2^18423998 is an apocalyptic number.

18423998 is a deficient number, since it is larger than the sum of its proper divisors (9212002).

18423998 is an equidigital number, since it uses as much as digits as its factorization.

18423998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9212001.

The product of its digits is 124416, while the sum is 44.

The square root of 18423998 is about 4292.3184877173. The cubic root of 18423998 is about 264.1159480737.

The spelling of 18423998 in words is "eighteen million, four hundred twenty-three thousand, nine hundred ninety-eight".