18858197 has 4 divisors (see below), whose sum is σ = 19367916. Its totient is φ = 18348480.

The previous prime is 18858193. The next prime is 18858221. The reversal of 18858197 is 79185881.

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

It can be written as a sum of positive squares in 2 ways, for example, as 13293316 + 5564881 = 3646^2 + 2359^2 .

It is a cyclic number.

It is not a de Polignac number, because 18858197 - 2² = 18858193 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 (18858193) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 254804 + ... + 254877.

It is an arithmetic number, because the mean of its divisors is an integer number (4841979).

Almost surely, 2^18858197 is an apocalyptic number.

It is an amenable number.

18858197 is a deficient number, since it is larger than the sum of its proper divisors (509719).

18858197 is an equidigital number, since it uses as much as digits as its factorization.

18858197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 509718.

The product of its digits is 161280, while the sum is 47.

The square root of 18858197 is about 4342.6025606772. The cubic root of 18858197 is about 266.1746690423.

It can be divided in two parts, 188 and 58197, that added together give a palindrome (58385).

The spelling of 18858197 in words is "eighteen million, eight hundred fifty-eight thousand, one hundred ninety-seven".