18013809 has 8 divisors (see below), whose sum is σ = 26201952. Its totient is φ = 10917440.

The previous prime is 18013781. The next prime is 18013813. The reversal of 18013809 is 90831081.

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 18013809 - 2⁵ = 18013777 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18013819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 272904 + ... + 272969.

It is an arithmetic number, because the mean of its divisors is an integer number (3275244).

Almost surely, 2^18013809 is an apocalyptic number.

It is an amenable number.

18013809 is a deficient number, since it is larger than the sum of its proper divisors (8188143).

18013809 is a wasteful number, since it uses less digits than its factorization.

18013809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 545887.

The product of its (nonzero) digits is 1728, while the sum is 30.

The square root of 18013809 is about 4244.2677813729. The cubic root of 18013809 is about 262.1411404715.

The spelling of 18013809 in words is "eighteen million, thirteen thousand, eight hundred nine".