667971 has 6 divisors (see below), whose sum is σ = 964860. Its totient is φ = 445308.

The previous prime is 667963. The next prime is 667987. The reversal of 667971 is 179766.

It is not a de Polignac number, because 667971 - 2³ = 667963 is a prime.

667971 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (667921) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 37101 + ... + 37118.

It is an arithmetic number, because the mean of its divisors is an integer number (160810).

2⁶⁶⁷⁹⁷¹ is an apocalyptic number.

667971 is a deficient number, since it is larger than the sum of its proper divisors (296889).

667971 is a wasteful number, since it uses less digits than its factorization.

667971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74225 (or 74222 counting only the distinct ones).

The product of its digits is 15876, while the sum is 36.

The square root of 667971 is about 817.2949284071. The cubic root of 667971 is about 87.4149813647.

The spelling of 667971 in words is "six hundred sixty-seven thousand, nine hundred seventy-one".