66109 has 2 divisors, whose sum is σ = 66110. Its totient is φ = 66108.

The previous prime is 66107. The next prime is 66137. The reversal of 66109 is 90166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60025 + 6084 = 245^2 + 78^2 .

It is a cyclic number.

It is not a de Polignac number, because 66109 - 2¹ = 66107 is a prime.

Together with 66107, it forms a pair of twin primes.

It is a Chen prime.

66109 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 66109.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33054 + 33055.

It is an arithmetic number, because the mean of its divisors is an integer number (33055).

2⁶⁶¹⁰⁹ is an apocalyptic number.

It is an amenable number.

66109 is a deficient number, since it is larger than the sum of its proper divisors (1).

66109 is an equidigital number, since it uses as much as digits as its factorization.

66109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 66109 is about 257.1167050193. The cubic root of 66109 is about 40.4346352007.

The spelling of 66109 in words is "sixty-six thousand, one hundred nine".