16718809 has 2 divisors, whose sum is σ = 16718810. Its totient is φ = 16718808.

The previous prime is 16718743. The next prime is 16718813. The reversal of 16718809 is 90881761.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12425625 + 4293184 = 3525^2 + 2072^2 .

It is a cyclic number.

It is not a de Polignac number, because 16718809 - 2¹¹ = 16716761 is a prime.

It is not a weakly prime, because it can be changed into another prime (16718839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8359404 + 8359405.

It is an arithmetic number, because the mean of its divisors is an integer number (8359405).

Almost surely, 2^16718809 is an apocalyptic number.

It is an amenable number.

16718809 is a deficient number, since it is larger than the sum of its proper divisors (1).

16718809 is an equidigital number, since it uses as much as digits as its factorization.

16718809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 40.

The square root of 16718809 is about 4088.8640231732. The cubic root of 16718809 is about 255.7025812308.

The spelling of 16718809 in words is "sixteen million, seven hundred eighteen thousand, eight hundred nine".