18108397 has 4 divisors (see below), whose sum is σ = 18143676. Its totient is φ = 18073120.

The previous prime is 18108367. The next prime is 18108401. The reversal of 18108397 is 79380181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79380181 = 31 ⋅2560651.

It can be written as a sum of positive squares in 2 ways, for example, as 4778596 + 13329801 = 2186^2 + 3651^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18108397 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 (18108317) 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, 16858 + ... + 17899.

It is an arithmetic number, because the mean of its divisors is an integer number (4535919).

Almost surely, 2^18108397 is an apocalyptic number.

It is an amenable number.

18108397 is a deficient number, since it is larger than the sum of its proper divisors (35279).

18108397 is an equidigital number, since it uses as much as digits as its factorization.

18108397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35278.

The product of its (nonzero) digits is 12096, while the sum is 37.

The square root of 18108397 is about 4255.3962212701. The cubic root of 18108397 is about 262.5991619312.

The spelling of 18108397 in words is "eighteen million, one hundred eight thousand, three hundred ninety-seven".