668671 has 2 divisors, whose sum is σ = 668672. Its totient is φ = 668670.

The previous prime is 668623. The next prime is 668677. The reversal of 668671 is 176866.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 668671 - 2⁷ = 668543 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334335 + 334336.

It is an arithmetic number, because the mean of its divisors is an integer number (334336).

2⁶⁶⁸⁶⁷¹ is an apocalyptic number.

668671 is a deficient number, since it is larger than the sum of its proper divisors (1).

668671 is an equidigital number, since it uses as much as digits as its factorization.

668671 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12096, while the sum is 34.

The square root of 668671 is about 817.7230582538. The cubic root of 668671 is about 87.4455062051.

The spelling of 668671 in words is "six hundred sixty-eight thousand, six hundred seventy-one".