18291197 has 4 divisors (see below), whose sum is σ = 18453180. Its totient is φ = 18129216.

The previous prime is 18291179. The next prime is 18291241. The reversal of 18291197 is 79119281.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79119281 = 137 ⋅577513.

It can be written as a sum of positive squares in 2 ways, for example, as 5410276 + 12880921 = 2326^2 + 3589^2 .

It is a cyclic number.

It is not a de Polignac number, because 18291197 - 2⁸ = 18290941 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 18291197.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18291157) 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, 80822 + ... + 81047.

It is an arithmetic number, because the mean of its divisors is an integer number (4613295).

Almost surely, 2^18291197 is an apocalyptic number.

It is an amenable number.

18291197 is a deficient number, since it is larger than the sum of its proper divisors (161983).

18291197 is a wasteful number, since it uses less digits than its factorization.

18291197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161982.

The product of its digits is 9072, while the sum is 38.

The square root of 18291197 is about 4276.8208987518. The cubic root of 18291197 is about 263.4798307148.

The spelling of 18291197 in words is "eighteen million, two hundred ninety-one thousand, one hundred ninety-seven".