855639 has 6 divisors (see below), whose sum is σ = 1235936. Its totient is φ = 570420.

The previous prime is 855619. The next prime is 855641. The reversal of 855639 is 936558.

It is not a de Polignac number, because 855639 - 2⁵ = 855607 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (855619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 47527 + ... + 47544.

2⁸⁵⁵⁶³⁹ is an apocalyptic number.

855639 is a deficient number, since it is larger than the sum of its proper divisors (380297).

855639 is a wasteful number, since it uses less digits than its factorization.

855639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95077 (or 95074 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 855639 is about 925.0075675366. The cubic root of 855639 is about 94.9358384859.

The spelling of 855639 in words is "eight hundred fifty-five thousand, six hundred thirty-nine".