666959 has 2 divisors, whose sum is σ = 666960. Its totient is φ = 666958.

The previous prime is 666937. The next prime is 666979. The reversal of 666959 is 959666.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 666959 - 2¹⁶ = 601423 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666929) 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, 333479 + 333480.

It is an arithmetic number, because the mean of its divisors is an integer number (333480).

2⁶⁶⁶⁹⁵⁹ is an apocalyptic number.

666959 is a deficient number, since it is larger than the sum of its proper divisors (1).

666959 is an equidigital number, since it uses as much as digits as its factorization.

666959 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 87480, while the sum is 41.

The square root of 666959 is about 816.6755781827. The cubic root of 666959 is about 87.3708134422.

The spelling of 666959 in words is "six hundred sixty-six thousand, nine hundred fifty-nine".