18705223 has 4 divisors (see below), whose sum is σ = 19011928. Its totient is φ = 18398520.

The previous prime is 18705217. The next prime is 18705227. The reversal of 18705223 is 32250781.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18705223 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18705191 and 18705200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18705227) 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, 153261 + ... + 153382.

It is an arithmetic number, because the mean of its divisors is an integer number (4752982).

Almost surely, 2^18705223 is an apocalyptic number.

18705223 is a deficient number, since it is larger than the sum of its proper divisors (306705).

18705223 is an equidigital number, since it uses as much as digits as its factorization.

18705223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306704.

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 18705223 is about 4324.9535257619. The cubic root of 18705223 is about 265.4529952264.

The spelling of 18705223 in words is "eighteen million, seven hundred five thousand, two hundred twenty-three".