1666201 has 2 divisors, whose sum is σ = 1666202. Its totient is φ = 1666200.

The previous prime is 1666177. The next prime is 1666211. The reversal of 1666201 is 1026661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1628176 + 38025 = 1276^2 + 195^2 .

It is an emirp because it is prime and its reverse (1026661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1666201 - 2⁹ = 1665689 is a prime.

It is not a weakly prime, because it can be changed into another prime (1666211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833100 + 833101.

It is an arithmetic number, because the mean of its divisors is an integer number (833101).

2^1666201 is an apocalyptic number.

It is an amenable number.

1666201 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666201 is an equidigital number, since it uses as much as digits as its factorization.

1666201 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 1666201 is about 1290.8140842120. The cubic root of 1666201 is about 118.5520669435.

The spelling of 1666201 in words is "one million, six hundred sixty-six thousand, two hundred one".