18969309 has 14 divisors (see below), whose sum is σ = 28442046. Its totient is φ = 12645720.

The previous prime is 18969299. The next prime is 18969317. The reversal of 18969309 is 90396981.

It can be written as a sum of positive squares in only one way, i.e., 18896409 + 72900 = 4347^2 + 270^2 .

It is not a de Polignac number, because 18969309 - 2⁹ = 18968797 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18969359) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 12282 + ... + 13739.

Almost surely, 2^18969309 is an apocalyptic number.

It is an amenable number.

18969309 is a deficient number, since it is larger than the sum of its proper divisors (9472737).

18969309 is an frugal number, since it uses more digits than its factorization.

18969309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26039 (or 26024 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 45.

The square root of 18969309 is about 4355.3770215677. The cubic root of 18969309 is about 266.6964103976.

The spelling of 18969309 in words is "eighteen million, nine hundred sixty-nine thousand, three hundred nine".