16808681 has 2 divisors, whose sum is σ = 16808682. Its totient is φ = 16808680.

The previous prime is 16808677. The next prime is 16808683. The reversal of 16808681 is 18680861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11560000 + 5248681 = 3400^2 + 2291^2 .

It is an emirp because it is prime and its reverse (18680861) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16808681 - 2² = 16808677 is a prime.

It is a super-2 number, since 2×16808681² = 565063513919522, which contains 22 as substring.

Together with 16808683, 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 (16808683) 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, 8404340 + 8404341.

It is an arithmetic number, because the mean of its divisors is an integer number (8404341).

Almost surely, 2^16808681 is an apocalyptic number.

It is an amenable number.

16808681 is a deficient number, since it is larger than the sum of its proper divisors (1).

16808681 is an equidigital number, since it uses as much as digits as its factorization.

16808681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18432, while the sum is 38.

The square root of 16808681 is about 4099.8391431860. The cubic root of 16808681 is about 256.1599393210.

The spelling of 16808681 in words is "sixteen million, eight hundred eight thousand, six hundred eighty-one".