18350509 has 4 divisors (see below), whose sum is σ = 18361216. Its totient is φ = 18339804.

The previous prime is 18350503. The next prime is 18350513. The reversal of 18350509 is 90505381.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 18350509 - 2⁹ = 18349997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18350503) 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, 2139 + ... + 6424.

It is an arithmetic number, because the mean of its divisors is an integer number (4590304).

Almost surely, 2^18350509 is an apocalyptic number.

It is an amenable number.

18350509 is a deficient number, since it is larger than the sum of its proper divisors (10707).

18350509 is an equidigital number, since it uses as much as digits as its factorization.

18350509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10706.

The product of its (nonzero) digits is 5400, while the sum is 31.

The square root of 18350509 is about 4283.7494091041. The cubic root of 18350509 is about 263.7643146398.

The spelling of 18350509 in words is "eighteen million, three hundred fifty thousand, five hundred nine".