18768509 has 12 divisors (see below), whose sum is σ = 19740924. Its totient is φ = 17829504.

The previous prime is 18768499. The next prime is 18768517. The reversal of 18768509 is 90586781.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 7546009 + 11222500 = 2747^2 + 3350^2 .

It is not a de Polignac number, because 18768509 - 2²⁴ = 1991293 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18768509.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18768569) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 166037 + ... + 166149.

It is an arithmetic number, because the mean of its divisors is an integer number (1645077).

Almost surely, 2^18768509 is an apocalyptic number.

It is an amenable number.

18768509 is a deficient number, since it is larger than the sum of its proper divisors (972415).

18768509 is an equidigital number, since it uses as much as digits as its factorization.

18768509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284 (or 217 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 44.

The square root of 18768509 is about 4332.2637269677. The cubic root of 18768509 is about 265.7520302024.

The spelling of 18768509 in words is "eighteen million, seven hundred sixty-eight thousand, five hundred nine".