6439855 has 16 divisors (see below), whose sum is σ = 8242560. Its totient is φ = 4813312.

The previous prime is 6439837. The next prime is 6439903. The reversal of 6439855 is 5589346.

It is not a de Polignac number, because 6439855 - 2¹¹ = 6437807 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20157 + ... + 20473.

It is an arithmetic number, because the mean of its divisors is an integer number (515160).

Almost surely, 2^6439855 is an apocalyptic number.

6439855 is a deficient number, since it is larger than the sum of its proper divisors (1802705).

6439855 is a wasteful number, since it uses less digits than its factorization.

6439855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 578.

The product of its digits is 129600, while the sum is 40.

The square root of 6439855 is about 2537.6869389269. The cubic root of 6439855 is about 186.0481530239.

The spelling of 6439855 in words is "six million, four hundred thirty-nine thousand, eight hundred fifty-five".