666671 has 2 divisors, whose sum is σ = 666672. Its totient is φ = 666670.

The previous prime is 666667. The next prime is 666683. The reversal of 666671 is 176666.

666671 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 666671 - 2² = 666667 is a 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 (666871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333335 + 333336.

It is an arithmetic number, because the mean of its divisors is an integer number (333336).

2⁶⁶⁶⁶⁷¹ is an apocalyptic number.

666671 is a deficient number, since it is larger than the sum of its proper divisors (1).

666671 is an equidigital number, since it uses as much as digits as its factorization.

666671 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9072, while the sum is 32.

The square root of 666671 is about 816.4992345373. The cubic root of 666671 is about 87.3582357490.

The spelling of 666671 in words is "six hundred sixty-six thousand, six hundred seventy-one".