667671 has 4 divisors (see below), whose sum is σ = 890232. Its totient is φ = 445112.

The previous prime is 667657. The next prime is 667673. The reversal of 667671 is 176766.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 667671 - 2¹⁰ = 666647 is a prime.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667673) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111276 + ... + 111281.

It is an arithmetic number, because the mean of its divisors is an integer number (222558).

2⁶⁶⁷⁶⁷¹ is an apocalyptic number.

667671 is a deficient number, since it is larger than the sum of its proper divisors (222561).

667671 is a wasteful number, since it uses less digits than its factorization.

667671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222560.

The product of its digits is 10584, while the sum is 33.

The square root of 667671 is about 817.1113755174. Note that the first 3 decimals coincide. The cubic root of 667671 is about 87.4018927619.

The spelling of 667671 in words is "six hundred sixty-seven thousand, six hundred seventy-one".