166865969 has 2 divisors, whose sum is σ = 166865970. Its totient is φ = 166865968.

The previous prime is 166865957. The next prime is 166865977. The reversal of 166865969 is 969568661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 160985344 + 5880625 = 12688^2 + 2425^2 .

It is an emirp because it is prime and its reverse (969568661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166865969 - 2¹² = 166861873 is a prime.

It is a super-2 number, since 2×166865969² = 55688503220617922, 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 (166835969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83432984 + 83432985.

It is an arithmetic number, because the mean of its divisors is an integer number (83432985).

Almost surely, 2^166865969 is an apocalyptic number.

It is an amenable number.

166865969 is a deficient number, since it is larger than the sum of its proper divisors (1).

166865969 is an equidigital number, since it uses as much as digits as its factorization.

166865969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4199040, while the sum is 56.

The square root of 166865969 is about 12917.6611273094. The cubic root of 166865969 is about 550.5404813707.

The spelling of 166865969 in words is "one hundred sixty-six million, eight hundred sixty-five thousand, nine hundred sixty-nine".