668871 has 16 divisors (see below), whose sum is σ = 1132800. Its totient is φ = 382104.

The previous prime is 668869. The next prime is 668873. The reversal of 668871 is 178866.

668871 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (668869) and next prime (668873).

It is not a de Polignac number, because 668871 - 2¹ = 668869 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668873) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1581 + ... + 1958.

It is an arithmetic number, because the mean of its divisors is an integer number (70800).

2⁶⁶⁸⁸⁷¹ is an apocalyptic number.

668871 is a deficient number, since it is larger than the sum of its proper divisors (463929).

668871 is a wasteful number, since it uses less digits than its factorization.

668871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3555 (or 3549 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 668871 is about 817.8453399024. The cubic root of 668871 is about 87.4542236750.

The spelling of 668871 in words is "six hundred sixty-eight thousand, eight hundred seventy-one".