18225689 has 4 divisors (see below), whose sum is σ = 18670260. Its totient is φ = 17781120.

The previous prime is 18225673. The next prime is 18225733. The reversal of 18225689 is 98652281.

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 9815689 + 8410000 = 3133^2 + 2900^2 .

It is a cyclic number.

It is not a de Polignac number, because 18225689 - 2⁴ = 18225673 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41), and also a Moran number because the ratio is a prime number: 444529 = 18225689 / (1 + 8 + 2 + 2 + 5 + 6 + 8 + 9).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18225089) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 222224 + ... + 222305.

It is an arithmetic number, because the mean of its divisors is an integer number (4667565).

Almost surely, 2^18225689 is an apocalyptic number.

It is an amenable number.

18225689 is a deficient number, since it is larger than the sum of its proper divisors (444571).

18225689 is an equidigital number, since it uses as much as digits as its factorization.

18225689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 444570.

The product of its digits is 69120, while the sum is 41.

The square root of 18225689 is about 4269.1555371057. The cubic root of 18225689 is about 263.1649126907.

The spelling of 18225689 in words is "eighteen million, two hundred twenty-five thousand, six hundred eighty-nine".