18118397 has 4 divisors (see below), whose sum is σ = 19765536. Its totient is φ = 16471260.

The previous prime is 18118367. The next prime is 18118469. The reversal of 18118397 is 79381181.

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, and also an emirpimes, since its reverse is a distinct semiprime: 79381181 = 11 ⋅7216471.

It is a cyclic number.

It is not a de Polignac number, because 18118397 - 2¹⁴ = 18102013 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 18118397.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18118327) 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, 823553 + ... + 823574.

It is an arithmetic number, because the mean of its divisors is an integer number (4941384).

Almost surely, 2^18118397 is an apocalyptic number.

It is an amenable number.

18118397 is a deficient number, since it is larger than the sum of its proper divisors (1647139).

18118397 is a wasteful number, since it uses less digits than its factorization.

18118397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1647138.

The product of its digits is 12096, while the sum is 38.

The square root of 18118397 is about 4256.5710378191. The cubic root of 18118397 is about 262.6474914140.

The spelling of 18118397 in words is "eighteen million, one hundred eighteen thousand, three hundred ninety-seven".