18069509 has 4 divisors (see below), whose sum is σ = 18078060. Its totient is φ = 18060960.

The previous prime is 18069473. The next prime is 18069511. The reversal of 18069509 is 90596081.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 7409284 + 10660225 = 2722^2 + 3265^2 .

It is a cyclic number.

It is not a de Polignac number, because 18069509 - 2⁸ = 18069253 is a prime.

It is a Duffinian number.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18069529) 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, 1457 + ... + 6185.

It is an arithmetic number, because the mean of its divisors is an integer number (4519515).

Almost surely, 2^18069509 is an apocalyptic number.

It is an amenable number.

18069509 is a deficient number, since it is larger than the sum of its proper divisors (8551).

18069509 is an equidigital number, since it uses as much as digits as its factorization.

18069509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8550.

The product of its (nonzero) digits is 19440, while the sum is 38.

The square root of 18069509 is about 4250.8245082572. The cubic root of 18069509 is about 262.4110489241.

The spelling of 18069509 in words is "eighteen million, sixty-nine thousand, five hundred nine".