1666249 has 4 divisors (see below), whose sum is σ = 1794436. Its totient is φ = 1538064.

The previous prime is 1666237. The next prime is 1666261. The reversal of 1666249 is 9426661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9426661 = 181 ⋅52081.

It is an interprime number because it is at equal distance from previous prime (1666237) and next prime (1666261).

It can be written as a sum of positive squares in 2 ways, for example, as 1140624 + 525625 = 1068^2 + 725^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1666249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1666279) 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, 64074 + ... + 64099.

It is an arithmetic number, because the mean of its divisors is an integer number (448609).

2^1666249 is an apocalyptic number.

It is an amenable number.

1666249 is a deficient number, since it is larger than the sum of its proper divisors (128187).

1666249 is a wasteful number, since it uses less digits than its factorization.

1666249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128186.

The product of its digits is 15552, while the sum is 34.

The square root of 1666249 is about 1290.8326769957. The cubic root of 1666249 is about 118.5532053504.

The spelling of 1666249 in words is "one million, six hundred sixty-six thousand, two hundred forty-nine".