18782009 has 2 divisors, whose sum is σ = 18782010. Its totient is φ = 18782008.

The previous prime is 18781993. The next prime is 18782047. The reversal of 18782009 is 90028781.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15642025 + 3139984 = 3955^2 + 1772^2 .

It is a cyclic number.

It is not a de Polignac number, because 18782009 - 2⁴ = 18781993 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18782009.

It is not a weakly prime, because it can be changed into another prime (18782509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9391004 + 9391005.

It is an arithmetic number, because the mean of its divisors is an integer number (9391005).

Almost surely, 2^18782009 is an apocalyptic number.

It is an amenable number.

18782009 is a deficient number, since it is larger than the sum of its proper divisors (1).

18782009 is an equidigital number, since it uses as much as digits as its factorization.

18782009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8064, while the sum is 35.

The square root of 18782009 is about 4333.8215237824. The cubic root of 18782009 is about 265.8157325200.

The spelling of 18782009 in words is "eighteen million, seven hundred eighty-two thousand, nine".