166651213 has 2 divisors, whose sum is σ = 166651214. Its totient is φ = 166651212.

The previous prime is 166651201. The next prime is 166651217. The reversal of 166651213 is 312156661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 164301124 + 2350089 = 12818^2 + 1533^2 .

It is an emirp because it is prime and its reverse (312156661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166651213 - 2²⁵ = 133096781 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166651217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83325606 + 83325607.

It is an arithmetic number, because the mean of its divisors is an integer number (83325607).

Almost surely, 2^166651213 is an apocalyptic number.

It is an amenable number.

166651213 is a deficient number, since it is larger than the sum of its proper divisors (1).

166651213 is an equidigital number, since it uses as much as digits as its factorization.

166651213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6480, while the sum is 31.

The square root of 166651213 is about 12909.3459555471. The cubic root of 166651213 is about 550.3041986624.

The spelling of 166651213 in words is "one hundred sixty-six million, six hundred fifty-one thousand, two hundred thirteen".