18693397 has 4 divisors (see below), whose sum is σ = 19677280. Its totient is φ = 17709516.

The previous prime is 18693373. The next prime is 18693413. The reversal of 18693397 is 79339681.

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: 79339681 = 191 ⋅415391.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18693397 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 (18693317) 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, 491913 + ... + 491950.

It is an arithmetic number, because the mean of its divisors is an integer number (4919320).

Almost surely, 2^18693397 is an apocalyptic number.

It is an amenable number.

18693397 is a deficient number, since it is larger than the sum of its proper divisors (983883).

18693397 is an equidigital number, since it uses as much as digits as its factorization.

18693397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 983882.

The product of its digits is 244944, while the sum is 46.

The square root of 18693397 is about 4323.5861272791. The cubic root of 18693397 is about 265.3970409986.

The spelling of 18693397 in words is "eighteen million, six hundred ninety-three thousand, three hundred ninety-seven".