491666 has 24 divisors (see below), whose sum is σ = 892620. Its totient is φ = 202272.

The previous prime is 491653. The next prime is 491669. The reversal of 491666 is 666194.

It can be written as a sum of positive squares in 2 ways, for example, as 461041 + 30625 = 679^2 + 175^2 .

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 491666.

It is not an unprimeable number, because it can be changed into a prime (491669) by changing a digit.

491666 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2756 + ... + 2928.

2⁴⁹¹⁶⁶⁶ is an apocalyptic number.

491666 is a deficient number, since it is larger than the sum of its proper divisors (400954).

491666 is a wasteful number, since it uses less digits than its factorization.

491666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218 (or 211 counting only the distinct ones).

The product of its digits is 7776, while the sum is 32.

The square root of 491666 is about 701.1889902159. The cubic root of 491666 is about 78.9265995582.

The spelling of 491666 in words is "four hundred ninety-one thousand, six hundred sixty-six".