166816669 has 2 divisors, whose sum is σ = 166816670. Its totient is φ = 166816668.

The previous prime is 166816649. The next prime is 166816679. The reversal of 166816669 is 966618661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 163712025 + 3104644 = 12795^2 + 1762^2 .

It is an emirp because it is prime and its reverse (966618661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166816669 - 2⁹ = 166816157 is a prime.

It is a super-3 number, since 3×166816669³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166816649) 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, 83408334 + 83408335.

It is an arithmetic number, because the mean of its divisors is an integer number (83408335).

Almost surely, 2^166816669 is an apocalyptic number.

It is an amenable number.

166816669 is a deficient number, since it is larger than the sum of its proper divisors (1).

166816669 is an equidigital number, since it uses as much as digits as its factorization.

166816669 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 559872, while the sum is 49.

The square root of 166816669 is about 12915.7527461623. The cubic root of 166816669 is about 550.4862575740.

The spelling of 166816669 in words is "one hundred sixty-six million, eight hundred sixteen thousand, six hundred sixty-nine".