16505009 has 2 divisors, whose sum is σ = 16505010. Its totient is φ = 16505008.

The previous prime is 16505003. The next prime is 16505017. The reversal of 16505009 is 90050561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10240000 + 6265009 = 3200^2 + 2503^2 .

It is a cyclic number.

It is not a de Polignac number, because 16505009 - 2⁴ = 16504993 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (16505003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8252504 + 8252505.

It is an arithmetic number, because the mean of its divisors is an integer number (8252505).

Almost surely, 2^16505009 is an apocalyptic number.

It is an amenable number.

16505009 is a deficient number, since it is larger than the sum of its proper divisors (1).

16505009 is an equidigital number, since it uses as much as digits as its factorization.

16505009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1350, while the sum is 26.

The square root of 16505009 is about 4062.6357208098. The cubic root of 16505009 is about 254.6079275348.

The spelling of 16505009 in words is "sixteen million, five hundred five thousand, nine".