18464209 has 3 divisors (see below), whose sum is σ = 18468507. Its totient is φ = 18459912.

The previous prime is 18464203. The next prime is 18464231. The reversal of 18464209 is 90246481.

The square root of 18464209 is 4297.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 9891025 + 8573184 = 3145^2 + 2928^2 .

It is not a de Polignac number, because 18464209 - 2⁷ = 18464081 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18464203) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2149 + ... + 6445.

It is an arithmetic number, because the mean of its divisors is an integer number (6156169).

Almost surely, 2^18464209 is an apocalyptic number.

18464209 is the 4297-th square number.

18464209 is the 2149-th centered octagonal number.

It is an amenable number.

18464209 is a deficient number, since it is larger than the sum of its proper divisors (4298).

18464209 is an frugal number, since it uses more digits than its factorization.

18464209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8594 (or 4297 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 34.

The cubic root of 18464209 is about 264.3079557893.

The spelling of 18464209 in words is "eighteen million, four hundred sixty-four thousand, two hundred nine".