166520317 has 2 divisors, whose sum is σ = 166520318. Its totient is φ = 166520316.

The previous prime is 166520309. The next prime is 166520339. The reversal of 166520317 is 713025661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 163175076 + 3345241 = 12774^2 + 1829^2 .

It is a cyclic number.

It is not a de Polignac number, because 166520317 - 2³ = 166520309 is a prime.

It is a super-3 number, since 3×166520317³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166520377) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83260158 + 83260159.

It is an arithmetic number, because the mean of its divisors is an integer number (83260159).

Almost surely, 2^166520317 is an apocalyptic number.

It is an amenable number.

166520317 is a deficient number, since it is larger than the sum of its proper divisors (1).

166520317 is an equidigital number, since it uses as much as digits as its factorization.

166520317 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7560, while the sum is 31.

The square root of 166520317 is about 12904.2751443078. The cubic root of 166520317 is about 550.1600823277.

Adding to 166520317 its reverse (713025661), we get a palindrome (879545978).

The spelling of 166520317 in words is "one hundred sixty-six million, five hundred twenty thousand, three hundred seventeen".