16842809 has 2 divisors, whose sum is σ = 16842810. Its totient is φ = 16842808.

The previous prime is 16842781. The next prime is 16842821. The reversal of 16842809 is 90824861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9703225 + 7139584 = 3115^2 + 2672^2 .

It is a cyclic number.

It is not a de Polignac number, because 16842809 - 2¹² = 16838713 is a prime.

It is a super-3 number, since 3×16842809³ (a number of 23 digits) contains 333 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (16842899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8421404 + 8421405.

It is an arithmetic number, because the mean of its divisors is an integer number (8421405).

Almost surely, 2^16842809 is an apocalyptic number.

It is an amenable number.

16842809 is a deficient number, since it is larger than the sum of its proper divisors (1).

16842809 is an equidigital number, since it uses as much as digits as its factorization.

16842809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27648, while the sum is 38.

The square root of 16842809 is about 4103.9991471734. Note that the first 3 decimals coincide. The cubic root of 16842809 is about 256.3331894091. Note that the first 3 decimals are identical.

The spelling of 16842809 in words is "sixteen million, eight hundred forty-two thousand, eight hundred nine".