18023997 has 4 divisors (see below), whose sum is σ = 24032000. Its totient is φ = 12015996.

The previous prime is 18023981. The next prime is 18024011. The reversal of 18023997 is 79932081.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 79932081 = 3 ⋅26644027.

It is not a de Polignac number, because 18023997 - 2⁴ = 18023981 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18023917) 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 3 ways as a sum of consecutive naturals, for example, 3003997 + ... + 3004002.

It is an arithmetic number, because the mean of its divisors is an integer number (6008000).

Almost surely, 2^18023997 is an apocalyptic number.

It is an amenable number.

18023997 is a deficient number, since it is larger than the sum of its proper divisors (6008003).

18023997 is an equidigital number, since it uses as much as digits as its factorization.

18023997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6008002.

The product of its (nonzero) digits is 27216, while the sum is 39.

The square root of 18023997 is about 4245.4678187451. The cubic root of 18023997 is about 262.1905505400.

The spelling of 18023997 in words is "eighteen million, twenty-three thousand, nine hundred ninety-seven".