16688081 has 2 divisors, whose sum is σ = 16688082. Its totient is φ = 16688080.

The previous prime is 16688059. The next prime is 16688093. The reversal of 16688081 is 18088661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16679056 + 9025 = 4084^2 + 95^2 .

It is an emirp because it is prime and its reverse (18088661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16688081 - 2⁶ = 16688017 is a prime.

It is a super-2 number, since 2×16688081² = 556984094925122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (16688011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8344040 + 8344041.

It is an arithmetic number, because the mean of its divisors is an integer number (8344041).

Almost surely, 2^16688081 is an apocalyptic number.

It is an amenable number.

16688081 is a deficient number, since it is larger than the sum of its proper divisors (1).

16688081 is an equidigital number, since it uses as much as digits as its factorization.

16688081 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 16688081 is about 4085.1047722182. The cubic root of 16688081 is about 255.5458306808.

The spelling of 16688081 in words is "sixteen million, six hundred eighty-eight thousand, eighty-one".