666427 has 2 divisors, whose sum is σ = 666428. Its totient is φ = 666426.

The previous prime is 666403. The next prime is 666431. The reversal of 666427 is 724666.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 666427 - 2¹¹ = 664379 is a prime.

It is not a weakly prime, because it can be changed into another prime (666437) 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, 333213 + 333214.

It is an arithmetic number, because the mean of its divisors is an integer number (333214).

2⁶⁶⁶⁴²⁷ is an apocalyptic number.

666427 is a deficient number, since it is larger than the sum of its proper divisors (1).

666427 is an equidigital number, since it uses as much as digits as its factorization.

666427 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 31.

The square root of 666427 is about 816.3498024744. The cubic root of 666427 is about 87.3475768130.

The spelling of 666427 in words is "six hundred sixty-six thousand, four hundred twenty-seven".