18162409 has 4 divisors (see below), whose sum is σ = 19230804. Its totient is φ = 17094016.

The previous prime is 18162359. The next prime is 18162413. The reversal of 18162409 is 90426181.

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 11256025 + 6906384 = 3355^2 + 2628^2 .

It is a cyclic number.

It is not a de Polignac number, because 18162409 - 2⁷ = 18162281 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18162509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 534172 + ... + 534205.

It is an arithmetic number, because the mean of its divisors is an integer number (4807701).

Almost surely, 2^18162409 is an apocalyptic number.

It is an amenable number.

18162409 is a deficient number, since it is larger than the sum of its proper divisors (1068395).

18162409 is a wasteful number, since it uses less digits than its factorization.

18162409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1068394.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 18162409 is about 4261.7377910895. The cubic root of 18162409 is about 262.8599880279.

It can be divided in two parts, 1816 and 2409, that added together give a square (4225 = 65²).

The spelling of 18162409 in words is "eighteen million, one hundred sixty-two thousand, four hundred nine".