1666993 has 4 divisors (see below), whose sum is σ = 1673460. Its totient is φ = 1660528.

The previous prime is 1666991. The next prime is 1666999. The reversal of 1666993 is 3996661.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 339889 + 1327104 = 583^2 + 1152^2 .

It is a cyclic number.

It is not a de Polignac number, because 1666993 - 2¹ = 1666991 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

1666993 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1666991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2830 + ... + 3367.

It is an arithmetic number, because the mean of its divisors is an integer number (418365).

2^1666993 is an apocalyptic number.

It is an amenable number.

1666993 is a deficient number, since it is larger than the sum of its proper divisors (6467).

1666993 is an equidigital number, since it uses as much as digits as its factorization.

1666993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6466.

The product of its digits is 52488, while the sum is 40.

The square root of 1666993 is about 1291.1208309062. The cubic root of 1666993 is about 118.5708478637.

The spelling of 1666993 in words is "one million, six hundred sixty-six thousand, nine hundred ninety-three".