66169309 has 2 divisors, whose sum is σ = 66169310. Its totient is φ = 66169308.

The previous prime is 66169307. The next prime is 66169333. The reversal of 66169309 is 90396166.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 35366809 + 30802500 = 5947^2 + 5550^2 .

It is a cyclic number.

It is not a de Polignac number, because 66169309 - 2¹ = 66169307 is a prime.

Together with 66169307, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66169307) 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, 33084654 + 33084655.

It is an arithmetic number, because the mean of its divisors is an integer number (33084655).

Almost surely, 2^66169309 is an apocalyptic number.

It is an amenable number.

66169309 is a deficient number, since it is larger than the sum of its proper divisors (1).

66169309 is an equidigital number, since it uses as much as digits as its factorization.

66169309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 52488, while the sum is 40.

The square root of 66169309 is about 8134.4519790825. The cubic root of 66169309 is about 404.4692717929.

The spelling of 66169309 in words is "sixty-six million, one hundred sixty-nine thousand, three hundred nine".