1666303 has 2 divisors, whose sum is σ = 1666304. Its totient is φ = 1666302.

The previous prime is 1666297. The next prime is 1666307. The reversal of 1666303 is 3036661.

It is a strong prime.

It is an emirp because it is prime and its reverse (3036661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1666303 - 2⁵ = 1666271 is a prime.

1666303 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1666307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833151 + 833152.

It is an arithmetic number, because the mean of its divisors is an integer number (833152).

2^1666303 is an apocalyptic number.

1666303 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666303 is an equidigital number, since it uses as much as digits as its factorization.

1666303 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1944, while the sum is 25.

The square root of 1666303 is about 1290.8535935574. The cubic root of 1666303 is about 118.5544860322.

The spelling of 1666303 in words is "one million, six hundred sixty-six thousand, three hundred three".