666849 has 8 divisors (see below), whose sum is σ = 894400. Its totient is φ = 441936.

The previous prime is 666829. The next prime is 666857. The reversal of 666849 is 948666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 666849 - 2¹⁶ = 601313 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666829) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39 + ... + 1155.

It is an arithmetic number, because the mean of its divisors is an integer number (111800).

2⁶⁶⁶⁸⁴⁹ is an apocalyptic number.

It is an amenable number.

666849 is a deficient number, since it is larger than the sum of its proper divisors (227551).

666849 is a wasteful number, since it uses less digits than its factorization.

666849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1319.

The product of its digits is 62208, while the sum is 39.

The square root of 666849 is about 816.6082292017. The cubic root of 666849 is about 87.3660098896.

The spelling of 666849 in words is "six hundred sixty-six thousand, eight hundred forty-nine".