666543 has 8 divisors (see below), whose sum is σ = 909568. Its totient is φ = 433944.

The previous prime is 666541. The next prime is 666557. The reversal of 666543 is 345666.

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

It is not a de Polignac number, because 666543 - 2¹ = 666541 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 666543.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666541) 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, 2455 + ... + 2712.

It is an arithmetic number, because the mean of its divisors is an integer number (113696).

2⁶⁶⁶⁵⁴³ is an apocalyptic number.

666543 is a deficient number, since it is larger than the sum of its proper divisors (243025).

666543 is a wasteful number, since it uses less digits than its factorization.

666543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5213.

The product of its digits is 12960, while the sum is 30.

The square root of 666543 is about 816.4208473575. The cubic root of 666543 is about 87.3526445004.

The spelling of 666543 in words is "six hundred sixty-six thousand, five hundred forty-three".