6687839 has 4 divisors (see below), whose sum is σ = 6693024. Its totient is φ = 6682656.

The previous prime is 6687823. The next prime is 6687853. The reversal of 6687839 is 9387866.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 9387866 = 2 ⋅4693933.

It is a cyclic number.

It is not a de Polignac number, because 6687839 - 2⁴ = 6687823 is a prime.

It is a Duffinian number.

Its product of digits (435456) is a multiple of the sum of its prime divisors (5184).

It is a junction number, because it is equal to n+sod(n) for n = 6687793 and 6687802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6687809) 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, 1034 + ... + 3800.

It is an arithmetic number, because the mean of its divisors is an integer number (1673256).

Almost surely, 2^6687839 is an apocalyptic number.

6687839 is a deficient number, since it is larger than the sum of its proper divisors (5185).

6687839 is a wasteful number, since it uses less digits than its factorization.

6687839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5184.

The product of its digits is 435456, while the sum is 47.

The square root of 6687839 is about 2586.0856521005. The cubic root of 6687839 is about 188.4062345143.

The spelling of 6687839 in words is "six million, six hundred eighty-seven thousand, eight hundred thirty-nine".