855909 has 6 divisors (see below), whose sum is σ = 1236326. Its totient is φ = 570600.

The previous prime is 855901. The next prime is 855919. The reversal of 855909 is 909558.

It can be written as a sum of positive squares in only one way, i.e., 656100 + 199809 = 810^2 + 447^2 .

It is not a de Polignac number, because 855909 - 2³ = 855901 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (855901) 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, 47542 + ... + 47559.

2⁸⁵⁵⁹⁰⁹ is an apocalyptic number.

It is an amenable number.

855909 is a deficient number, since it is larger than the sum of its proper divisors (380417).

855909 is a wasteful number, since it uses less digits than its factorization.

855909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95107 (or 95104 counting only the distinct ones).

The product of its (nonzero) digits is 16200, while the sum is 36.

The square root of 855909 is about 925.1535007770. The cubic root of 855909 is about 94.9458232188.

It can be divided in two parts, 855 and 909, that added together give a square (1764 = 42²).

The spelling of 855909 in words is "eight hundred fifty-five thousand, nine hundred nine".