6805139 has 16 divisors (see below), whose sum is σ = 7741440. Its totient is φ = 5928000.

The previous prime is 6805121. The next prime is 6805157. The reversal of 6805139 is 9315086.

Added to its reverse (9315086) it gives a square (16120225 = 4015²).

6805139 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (6805121) and next prime (6805157).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6805139 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6805109) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35534 + ... + 35724.

It is an arithmetic number, because the mean of its divisors is an integer number (483840).

Almost surely, 2^6805139 is an apocalyptic number.

6805139 is a deficient number, since it is larger than the sum of its proper divisors (936301).

6805139 is a wasteful number, since it uses less digits than its factorization.

6805139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322.

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 6805139 is about 2608.6661342533. Note that the first 3 decimals coincide. The cubic root of 6805139 is about 189.5013610222.

Adding to 6805139 its reverse (9315086), we get a square (16120225 = 4015²).

The spelling of 6805139 in words is "six million, eight hundred five thousand, one hundred thirty-nine".