18408197 has 4 divisors (see below), whose sum is σ = 18417036. Its totient is φ = 18399360.

The previous prime is 18408179. The next prime is 18408199. The reversal of 18408197 is 79180481.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 79180481 = 37 ⋅2140013.

It can be written as a sum of positive squares in 2 ways, for example, as 17048641 + 1359556 = 4129^2 + 1166^2 .

It is a cyclic number.

It is not a de Polignac number, because 18408197 - 2⁶ = 18408133 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18408197.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18408199) 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, 623 + ... + 6099.

It is an arithmetic number, because the mean of its divisors is an integer number (4604259).

Almost surely, 2^18408197 is an apocalyptic number.

It is an amenable number.

18408197 is a deficient number, since it is larger than the sum of its proper divisors (8839).

18408197 is an equidigital number, since it uses as much as digits as its factorization.

18408197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8838.

The product of its (nonzero) digits is 16128, while the sum is 38.

The square root of 18408197 is about 4290.4774792557. The cubic root of 18408197 is about 264.0404217644.

The spelling of 18408197 in words is "eighteen million, four hundred eight thousand, one hundred ninety-seven".