18009243 has 16 divisors (see below), whose sum is σ = 30492160. Its totient is φ = 10290888.

The previous prime is 18009227. The next prime is 18009259. The reversal of 18009243 is 34290081.

It is an interprime number because it is at equal distance from previous prime (18009227) and next prime (18009259).

It is not a de Polignac number, because 18009243 - 2⁴ = 18009227 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18009223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47455 + ... + 47832.

It is an arithmetic number, because the mean of its divisors is an integer number (1905760).

Almost surely, 2^18009243 is an apocalyptic number.

18009243 is a deficient number, since it is larger than the sum of its proper divisors (12482917).

18009243 is an equidigital number, since it uses as much as digits as its factorization.

18009243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95303 (or 95297 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 18009243 is about 4243.7298453130. The cubic root of 18009243 is about 262.1189901017.

The spelling of 18009243 in words is "eighteen million, nine thousand, two hundred forty-three".