18165997 has 4 divisors (see below), whose sum is σ = 18181440. Its totient is φ = 18150556.

The previous prime is 18165991. The next prime is 18166003. The reversal of 18165997 is 79956181.

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 an interprime number because it is at equal distance from previous prime (18165991) and next prime (18166003).

It is a cyclic number.

It is not a de Polignac number, because 18165997 - 2²³ = 9777389 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 (18165991) 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, 5797 + ... + 8362.

It is an arithmetic number, because the mean of its divisors is an integer number (4545360).

Almost surely, 2^18165997 is an apocalyptic number.

It is an amenable number.

18165997 is a deficient number, since it is larger than the sum of its proper divisors (15443).

18165997 is a wasteful number, since it uses less digits than its factorization.

18165997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15442.

The product of its digits is 136080, while the sum is 46.

The square root of 18165997 is about 4262.1587253410. The cubic root of 18165997 is about 262.8772962961.

The spelling of 18165997 in words is "eighteen million, one hundred sixty-five thousand, nine hundred ninety-seven".