16865909 has 2 divisors, whose sum is σ = 16865910. Its totient is φ = 16865908.

The previous prime is 16865881. The next prime is 16865911. The reversal of 16865909 is 90956861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16851025 + 14884 = 4105^2 + 122^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16865909 is a prime.

Together with 16865911, it forms a pair of twin primes.

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 16865909.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16865929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8432954 + 8432955.

It is an arithmetic number, because the mean of its divisors is an integer number (8432955).

Almost surely, 2^16865909 is an apocalyptic number.

It is an amenable number.

16865909 is a deficient number, since it is larger than the sum of its proper divisors (1).

16865909 is an equidigital number, since it uses as much as digits as its factorization.

16865909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 116640, while the sum is 44.

The square root of 16865909 is about 4106.8125109384. The cubic root of 16865909 is about 256.4503233090.

The spelling of 16865909 in words is "sixteen million, eight hundred sixty-five thousand, nine hundred nine".