18320434609 has 3 divisors (see below), whose sum is σ = 18320569963. Its totient is φ = 18320299256.

The previous prime is 18320434603. The next prime is 18320434673. The reversal of 18320434609 is 90643402381.

It is a happy number.

The square root of 18320434609 is 135353.

It is a perfect power (a square), and thus also a powerful number.

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 only one way, i.e., 12646127025 + 5674307584 = 112455^2 + 75328^2 .

It is not a de Polignac number, because 18320434609 - 2⁵ = 18320434577 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18320434603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 67677 + ... + 203029.

Almost surely, 2^18320434609 is an apocalyptic number.

18320434609 is the 135353-rd square number.

18320434609 is the 67677-th centered octagonal number.

It is an amenable number.

18320434609 is a deficient number, since it is larger than the sum of its proper divisors (135354).

18320434609 is an frugal number, since it uses more digits than its factorization.

18320434609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 270706 (or 135353 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 40.

It can be divided in two parts, 18320 and 434609, that added together give a square (452929 = 673²).

The spelling of 18320434609 in words is "eighteen billion, three hundred twenty million, four hundred thirty-four thousand, six hundred nine".