6856509 has 16 divisors (see below), whose sum is σ = 10039104. Its totient is φ = 4128000.

The previous prime is 6856483. The next prime is 6856517. The reversal of 6856509 is 9056586.

It is not a de Polignac number, because 6856509 - 2⁵ = 6856477 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6856529) 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, 5109 + ... + 6309.

It is an arithmetic number, because the mean of its divisors is an integer number (627444).

Almost surely, 2^6856509 is an apocalyptic number.

It is an amenable number.

6856509 is a deficient number, since it is larger than the sum of its proper divisors (3182595).

6856509 is a wasteful number, since it uses less digits than its factorization.

6856509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1388.

The product of its (nonzero) digits is 64800, while the sum is 39.

The square root of 6856509 is about 2618.4936509375. The cubic root of 6856509 is about 189.9769962916.

The spelling of 6856509 in words is "six million, eight hundred fifty-six thousand, five hundred nine".