166599869 has 2 divisors, whose sum is σ = 166599870. Its totient is φ = 166599868.

The previous prime is 166599857. The next prime is 166599871. The reversal of 166599869 is 968995661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 161925625 + 4674244 = 12725^2 + 2162^2 .

It is a cyclic number.

It is not a de Polignac number, because 166599869 - 2¹² = 166595773 is a prime.

It is a super-2 number, since 2×166599869² = 55511032701634322, which contains 22 as substring.

Together with 166599871, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166599889) 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, 83299934 + 83299935.

It is an arithmetic number, because the mean of its divisors is an integer number (83299935).

Almost surely, 2^166599869 is an apocalyptic number.

It is an amenable number.

166599869 is a deficient number, since it is larger than the sum of its proper divisors (1).

166599869 is an equidigital number, since it uses as much as digits as its factorization.

166599869 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6298560, while the sum is 59.

The square root of 166599869 is about 12907.3571655858. The cubic root of 166599869 is about 550.2476779797.

The spelling of 166599869 in words is "one hundred sixty-six million, five hundred ninety-nine thousand, eight hundred sixty-nine".