18143997 has 4 divisors (see below), whose sum is σ = 24192000. Its totient is φ = 12095996.

The previous prime is 18143989. The next prime is 18144001. The reversal of 18143997 is 79934181.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 18143997 - 2³ = 18143989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18143497) 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, 3023997 + ... + 3024002.

It is an arithmetic number, because the mean of its divisors is an integer number (6048000).

Almost surely, 2^18143997 is an apocalyptic number.

It is an amenable number.

18143997 is a deficient number, since it is larger than the sum of its proper divisors (6048003).

18143997 is an equidigital number, since it uses as much as digits as its factorization.

18143997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6048002.

The product of its digits is 54432, while the sum is 42.

The square root of 18143997 is about 4259.5770916841. The cubic root of 18143997 is about 262.7711339107.

The spelling of 18143997 in words is "eighteen million, one hundred forty-three thousand, nine hundred ninety-seven".