18286397 has 4 divisors (see below), whose sum is σ = 18586236. Its totient is φ = 17986560.

The previous prime is 18286393. The next prime is 18286483. The reversal of 18286397 is 79368281.

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 401956 + 17884441 = 634^2 + 4229^2 .

It is a cyclic number.

It is not a de Polignac number, because 18286397 - 2² = 18286393 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 (18286391) 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, 149828 + ... + 149949.

It is an arithmetic number, because the mean of its divisors is an integer number (4646559).

Almost surely, 2^18286397 is an apocalyptic number.

It is an amenable number.

18286397 is a deficient number, since it is larger than the sum of its proper divisors (299839).

18286397 is an equidigital number, since it uses as much as digits as its factorization.

18286397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299838.

The product of its digits is 145152, while the sum is 44.

The square root of 18286397 is about 4276.2596974459. The cubic root of 18286397 is about 263.4567811237.

The spelling of 18286397 in words is "eighteen million, two hundred eighty-six thousand, three hundred ninety-seven".