166602221 has 2 divisors, whose sum is σ = 166602222. Its totient is φ = 166602220.

The previous prime is 166602217. The next prime is 166602239. The reversal of 166602221 is 122206661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 160909225 + 5692996 = 12685^2 + 2386^2 .

It is a cyclic number.

It is not a de Polignac number, because 166602221 - 2² = 166602217 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166602421) 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, 83301110 + 83301111.

It is an arithmetic number, because the mean of its divisors is an integer number (83301111).

Almost surely, 2^166602221 is an apocalyptic number.

It is an amenable number.

166602221 is a deficient number, since it is larger than the sum of its proper divisors (1).

166602221 is an equidigital number, since it uses as much as digits as its factorization.

166602221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 166602221 is about 12907.4482760924. The cubic root of 166602221 is about 550.2502673704.

Adding to 166602221 its reverse (122206661), we get a palindrome (288808882).

It can be divided in two parts, 16660 and 2221, that added together give a palindrome (18881).

The spelling of 166602221 in words is "one hundred sixty-six million, six hundred two thousand, two hundred twenty-one".