666983 has 2 divisors, whose sum is σ = 666984. Its totient is φ = 666982.

The previous prime is 666979. The next prime is 666989. The reversal of 666983 is 389666.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 666983 - 2² = 666979 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666989) 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 as a sum of consecutive naturals, namely, 333491 + 333492.

It is an arithmetic number, because the mean of its divisors is an integer number (333492).

2⁶⁶⁶⁹⁸³ is an apocalyptic number.

666983 is a deficient number, since it is larger than the sum of its proper divisors (1).

666983 is an equidigital number, since it uses as much as digits as its factorization.

666983 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 46656, while the sum is 38.

The square root of 666983 is about 816.6902717677. The cubic root of 666983 is about 87.3718614198.

The spelling of 666983 in words is "six hundred sixty-six thousand, nine hundred eighty-three".