166564949 has 2 divisors, whose sum is σ = 166564950. Its totient is φ = 166564948.

The previous prime is 166564927. The next prime is 166564961. The reversal of 166564949 is 949465661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 155127025 + 11437924 = 12455^2 + 3382^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166564949 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 166564897 and 166564906.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166561949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83282474 + 83282475.

It is an arithmetic number, because the mean of its divisors is an integer number (83282475).

Almost surely, 2^166564949 is an apocalyptic number.

It is an amenable number.

166564949 is a deficient number, since it is larger than the sum of its proper divisors (1).

166564949 is an equidigital number, since it uses as much as digits as its factorization.

166564949 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1399680, while the sum is 50.

The square root of 166564949 is about 12906.0043778080. The cubic root of 166564949 is about 550.2092305874.

The spelling of 166564949 in words is "one hundred sixty-six million, five hundred sixty-four thousand, nine hundred forty-nine".