18997357 has 4 divisors (see below), whose sum is σ = 19439200. Its totient is φ = 18555516.

The previous prime is 18997343. The next prime is 18997361. The reversal of 18997357 is 75379981.

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.

It is a cyclic number.

It is not a de Polignac number, because 18997357 - 2⁷ = 18997229 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 18997357.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18997337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 220857 + ... + 220942.

It is an arithmetic number, because the mean of its divisors is an integer number (4859800).

Almost surely, 2^18997357 is an apocalyptic number.

It is an amenable number.

18997357 is a deficient number, since it is larger than the sum of its proper divisors (441843).

18997357 is an equidigital number, since it uses as much as digits as its factorization.

18997357 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 441842.

The product of its digits is 476280, while the sum is 49.

The square root of 18997357 is about 4358.5957601044. The cubic root of 18997357 is about 266.8277913413.

The spelling of 18997357 in words is "eighteen million, nine hundred ninety-seven thousand, three hundred fifty-seven".