667685 has 8 divisors (see below), whose sum is σ = 821016. Its totient is φ = 520960.

The previous prime is 667673. The next prime is 667687. The reversal of 667685 is 586766.

It can be written as a sum of positive squares in 4 ways, for example, as 37249 + 630436 = 193^2 + 794^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 667685 - 2¹² = 663589 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1424 + ... + 1833.

It is an arithmetic number, because the mean of its divisors is an integer number (102627).

2⁶⁶⁷⁶⁸⁵ is an apocalyptic number.

It is an amenable number.

667685 is a deficient number, since it is larger than the sum of its proper divisors (153331).

667685 is a wasteful number, since it uses less digits than its factorization.

667685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3303.

The product of its digits is 60480, while the sum is 38.

The square root of 667685 is about 817.1199422361. The cubic root of 667685 is about 87.4025036505.

The spelling of 667685 in words is "six hundred sixty-seven thousand, six hundred eighty-five".