166706521 has 2 divisors, whose sum is σ = 166706522. Its totient is φ = 166706520.

The previous prime is 166706483. The next prime is 166706531. The reversal of 166706521 is 125607661.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 154032921 + 12673600 = 12411^2 + 3560^2 .

It is a cyclic number.

It is not a de Polignac number, because 166706521 - 2²⁷ = 32488793 is a prime.

It is not a weakly prime, because it can be changed into another prime (166706531) 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, 83353260 + 83353261.

It is an arithmetic number, because the mean of its divisors is an integer number (83353261).

Almost surely, 2^166706521 is an apocalyptic number.

It is an amenable number.

166706521 is a deficient number, since it is larger than the sum of its proper divisors (1).

166706521 is an equidigital number, since it uses as much as digits as its factorization.

166706521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 166706521 is about 12911.4879467860. The cubic root of 166706521 is about 550.3650700229.

The spelling of 166706521 in words is "one hundred sixty-six million, seven hundred six thousand, five hundred twenty-one".