166648817 has 2 divisors, whose sum is σ = 166648818. Its totient is φ = 166648816.

The previous prime is 166648789. The next prime is 166648831. The reversal of 166648817 is 718846661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 145709041 + 20939776 = 12071^2 + 4576^2 .

It is a cyclic number.

It is not a de Polignac number, because 166648817 - 2¹² = 166644721 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (166648117) 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, 83324408 + 83324409.

It is an arithmetic number, because the mean of its divisors is an integer number (83324409).

Almost surely, 2^166648817 is an apocalyptic number.

It is an amenable number.

166648817 is a deficient number, since it is larger than the sum of its proper divisors (1).

166648817 is an equidigital number, since it uses as much as digits as its factorization.

166648817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 387072, while the sum is 47.

The square root of 166648817 is about 12909.2531542301. The cubic root of 166648817 is about 550.3015613475.

The spelling of 166648817 in words is "one hundred sixty-six million, six hundred forty-eight thousand, eight hundred seventeen".