18009415 has 4 divisors (see below), whose sum is σ = 21611304. Its totient is φ = 14407528.

The previous prime is 18009403. The next prime is 18009421. The reversal of 18009415 is 51490081.

It is a happy number.

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 18009415 - 2⁷ = 18009287 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1800937 + ... + 1800946.

It is an arithmetic number, because the mean of its divisors is an integer number (5402826).

Almost surely, 2^18009415 is an apocalyptic number.

18009415 is a deficient number, since it is larger than the sum of its proper divisors (3601889).

18009415 is an equidigital number, since it uses as much as digits as its factorization.

18009415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3601888.

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 18009415 is about 4243.7501104566. The cubic root of 18009415 is about 262.1198245681.

Adding to 18009415 its reverse (51490081), we get a palindrome (69499496).

The spelling of 18009415 in words is "eighteen million, nine thousand, four hundred fifteen".