18209227 has 4 divisors (see below), whose sum is σ = 19280376. Its totient is φ = 17138080.

The previous prime is 18209209. The next prime is 18209231. The reversal of 18209227 is 72290281.

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

It is a cyclic number.

It is not a de Polignac number, because 18209227 - 2⁷ = 18209099 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18209027) 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, 535549 + ... + 535582.

It is an arithmetic number, because the mean of its divisors is an integer number (4820094).

Almost surely, 2^18209227 is an apocalyptic number.

18209227 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

18209227 is a deficient number, since it is larger than the sum of its proper divisors (1071149).

18209227 is a wasteful number, since it uses less digits than its factorization.

18209227 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1071148.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 18209227 is about 4267.2270855908. The cubic root of 18209227 is about 263.0856559563.

The spelling of 18209227 in words is "eighteen million, two hundred nine thousand, two hundred twenty-seven".