1666849 has 4 divisors (see below), whose sum is σ = 1683136. Its totient is φ = 1650564.

The previous prime is 1666843. The next prime is 1666853. The reversal of 1666849 is 9486661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1666849 - 2¹¹ = 1664801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1666843) by changing a digit.

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

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7989 + ... + 8194.

It is an arithmetic number, because the mean of its divisors is an integer number (420784).

2^1666849 is an apocalyptic number.

It is an amenable number.

1666849 is a deficient number, since it is larger than the sum of its proper divisors (16287).

1666849 is a wasteful number, since it uses less digits than its factorization.

1666849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16286.

The product of its digits is 62208, while the sum is 40.

The square root of 1666849 is about 1291.0650642009. The cubic root of 1666849 is about 118.5674335934.

The spelling of 1666849 in words is "one million, six hundred sixty-six thousand, eight hundred forty-nine".