189782009 has 2 divisors, whose sum is σ = 189782010. Its totient is φ = 189782008.

The previous prime is 189781997. The next prime is 189782011. The reversal of 189782009 is 900287981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 110838784 + 78943225 = 10528^2 + 8885^2 .

It is an emirp because it is prime and its reverse (900287981) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-189782009 is a prime.

Together with 189782011, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (189782209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94891004 + 94891005.

It is an arithmetic number, because the mean of its divisors is an integer number (94891005).

Almost surely, 2^189782009 is an apocalyptic number.

It is an amenable number.

189782009 is a deficient number, since it is larger than the sum of its proper divisors (1).

189782009 is an equidigital number, since it uses as much as digits as its factorization.

189782009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72576, while the sum is 44.

The square root of 189782009 is about 13776.1391180548. The cubic root of 189782009 is about 574.6697627355.

The spelling of 189782009 in words is "one hundred eighty-nine million, seven hundred eighty-two thousand, nine".