667839 has 4 divisors (see below), whose sum is σ = 890456. Its totient is φ = 445224.

The previous prime is 667837. The next prime is 667859. The reversal of 667839 is 938766.

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

It is not a de Polignac number, because 667839 - 2¹ = 667837 is a prime.

It is a D-number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 667797 and 667806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111304 + ... + 111309.

It is an arithmetic number, because the mean of its divisors is an integer number (222614).

2⁶⁶⁷⁸³⁹ is an apocalyptic number.

667839 is a deficient number, since it is larger than the sum of its proper divisors (222617).

667839 is a wasteful number, since it uses less digits than its factorization.

667839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222616.

The product of its digits is 54432, while the sum is 39.

The square root of 667839 is about 817.2141702149. The cubic root of 667839 is about 87.4092228624.

The spelling of 667839 in words is "six hundred sixty-seven thousand, eight hundred thirty-nine".