18965009 has 12 divisors (see below), whose sum is σ = 22144500. Its totient is φ = 16194528.

The previous prime is 18964997. The next prime is 18965029. The reversal of 18965009 is 90056981.

It can be written as a sum of positive squares in 2 ways, for example, as 5664400 + 13300609 = 2380^2 + 3647^2 .

It is a de Polignac number, because none of the positive numbers 2^k-18965009 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18965029) 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, 16547 + ... + 17655.

It is an arithmetic number, because the mean of its divisors is an integer number (1845375).

Almost surely, 2^18965009 is an apocalyptic number.

It is an amenable number.

18965009 is a deficient number, since it is larger than the sum of its proper divisors (3179491).

18965009 is a wasteful number, since it uses less digits than its factorization.

18965009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1472 (or 1465 counting only the distinct ones).

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

The square root of 18965009 is about 4354.8833509062. The cubic root of 18965009 is about 266.6762571204.

The spelling of 18965009 in words is "eighteen million, nine hundred sixty-five thousand, nine".