166109969 has 2 divisors, whose sum is σ = 166109970. Its totient is φ = 166109968.

The previous prime is 166109947. The next prime is 166109971. The reversal of 166109969 is 969901661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 150798400 + 15311569 = 12280^2 + 3913^2 .

It is a cyclic number.

It is not a de Polignac number, because 166109969 - 2¹² = 166105873 is a prime.

It is a super-2 number, since 2×166109969² = 55185043602361922, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 166109971, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (166109869) 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, 83054984 + 83054985.

It is an arithmetic number, because the mean of its divisors is an integer number (83054985).

Almost surely, 2^166109969 is an apocalyptic number.

It is an amenable number.

166109969 is a deficient number, since it is larger than the sum of its proper divisors (1).

166109969 is an equidigital number, since it uses as much as digits as its factorization.

166109969 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 157464, while the sum is 47.

The square root of 166109969 is about 12888.3656450304. The cubic root of 166109969 is about 549.7077996101.

The spelling of 166109969 in words is "one hundred sixty-six million, one hundred nine thousand, nine hundred sixty-nine".