666443 has 4 divisors (see below), whose sum is σ = 668448. Its totient is φ = 664440.

The previous prime is 666439. The next prime is 666461. The reversal of 666443 is 344666.

666443 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 666443 - 2² = 666439 is a prime.

It is a d-powerful number, because it can be written as 6⁶ + 6⁶ + 4⁹ + 6⁶ + 4⁹ + 3⁷ .

It is a Duffinian number.

It is a nialpdrome in base 10.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 666443.

It is not an unprimeable number, because it can be changed into a prime (666403) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 371 + ... + 1212.

It is an arithmetic number, because the mean of its divisors is an integer number (167112).

2⁶⁶⁶⁴⁴³ is an apocalyptic number.

666443 is a deficient number, since it is larger than the sum of its proper divisors (2005).

666443 is a wasteful number, since it uses less digits than its factorization.

666443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2004.

The product of its digits is 10368, while the sum is 29.

The square root of 666443 is about 816.3596021362. The cubic root of 666443 is about 87.3482758393.

The spelling of 666443 in words is "six hundred sixty-six thousand, four hundred forty-three".