166565513 has 2 divisors, whose sum is σ = 166565514. Its totient is φ = 166565512.

The previous prime is 166565501. The next prime is 166565569. The reversal of 166565513 is 315565661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 87853129 + 78712384 = 9373^2 + 8872^2 .

It is a cyclic number.

It is not a de Polignac number, because 166565513 - 2⁸ = 166565257 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (166565213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83282756 + 83282757.

It is an arithmetic number, because the mean of its divisors is an integer number (83282757).

Almost surely, 2^166565513 is an apocalyptic number.

It is an amenable number.

166565513 is a deficient number, since it is larger than the sum of its proper divisors (1).

166565513 is an equidigital number, since it uses as much as digits as its factorization.

166565513 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 81000, while the sum is 38.

The square root of 166565513 is about 12906.0262280843. The cubic root of 166565513 is about 550.2098516017.

The spelling of 166565513 in words is "one hundred sixty-six million, five hundred sixty-five thousand, five hundred thirteen".