18162209 has 8 divisors (see below), whose sum is σ = 19597032. Its totient is φ = 16732800.

The previous prime is 18162173. The next prime is 18162217. The reversal of 18162209 is 90226181.

It can be written as a sum of positive squares in 4 ways, for example, as 4494400 + 13667809 = 2120^2 + 3697^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18162209 - 2¹² = 18158113 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18162259) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8117 + ... + 10109.

It is an arithmetic number, because the mean of its divisors is an integer number (2449629).

Almost surely, 2^18162209 is an apocalyptic number.

It is an amenable number.

18162209 is a deficient number, since it is larger than the sum of its proper divisors (1434823).

18162209 is a wasteful number, since it uses less digits than its factorization.

18162209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2707.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 18162209 is about 4261.7143264184. The cubic root of 18162209 is about 262.8590231744.

The spelling of 18162209 in words is "eighteen million, one hundred sixty-two thousand, two hundred nine".