18225309 has 8 divisors (see below), whose sum is σ = 25729920. Its totient is φ = 11435456.

The previous prime is 18225307. The next prime is 18225323. The reversal of 18225309 is 90352281.

It is a happy number.

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 18225309 - 2¹ = 18225307 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18225301) 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 7 ways as a sum of consecutive naturals, for example, 178629 + ... + 178730.

It is an arithmetic number, because the mean of its divisors is an integer number (3216240).

Almost surely, 2^18225309 is an apocalyptic number.

It is an amenable number.

18225309 is a deficient number, since it is larger than the sum of its proper divisors (7504611).

18225309 is a wasteful number, since it uses less digits than its factorization.

18225309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 357379.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 18225309 is about 4269.1110315849. Note that the first 3 decimals coincide. The cubic root of 18225309 is about 263.1630837089.

The spelling of 18225309 in words is "eighteen million, two hundred twenty-five thousand, three hundred nine".