18397873 has 4 divisors (see below), whose sum is σ = 19813108. Its totient is φ = 16982640.

The previous prime is 18397853. The next prime is 18397877. The reversal of 18397873 is 37879381.

It is a happy number.

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 9941409 + 8456464 = 3153^2 + 2908^2 .

It is a cyclic number.

It is not a de Polignac number, because 18397873 - 2⁹ = 18397361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18397877) 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, 707598 + ... + 707623.

It is an arithmetic number, because the mean of its divisors is an integer number (4953277).

Almost surely, 2^18397873 is an apocalyptic number.

18397873 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

18397873 is a deficient number, since it is larger than the sum of its proper divisors (1415235).

18397873 is a wasteful number, since it uses less digits than its factorization.

18397873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1415234.

The product of its digits is 254016, while the sum is 46.

The square root of 18397873 is about 4289.2741810241. The cubic root of 18397873 is about 263.9910513113.

The spelling of 18397873 in words is "eighteen million, three hundred ninety-seven thousand, eight hundred seventy-three".