6856407 has 20 divisors (see below), whose sum is σ = 10466016. Its totient is φ = 4471200.

The previous prime is 6856403. The next prime is 6856411. The reversal of 6856407 is 7046586.

It is a happy number.

6856407 is a `hidden beast` number, since 6 + 8 + 5 + 640 + 7 = 666.

It is an interprime number because it is at equal distance from previous prime (6856403) and next prime (6856411).

It is not a de Polignac number, because 6856407 - 2² = 6856403 is a prime.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6856403) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2907 + ... + 4707.

Almost surely, 2^6856407 is an apocalyptic number.

6856407 is a deficient number, since it is larger than the sum of its proper divisors (3609609).

6856407 is a wasteful number, since it uses less digits than its factorization.

6856407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1860 (or 1851 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The square root of 6856407 is about 2618.4741740181. The cubic root of 6856407 is about 189.9760542306.

The spelling of 6856407 in words is "six million, eight hundred fifty-six thousand, four hundred seven".