856825 has 6 divisors (see below), whose sum is σ = 1062494. Its totient is φ = 685440.

The previous prime is 856813. The next prime is 856831. The reversal of 856825 is 528658.

It can be written as a sum of positive squares in 3 ways, for example, as 190969 + 665856 = 437^2 + 816^2 .

It is not a de Polignac number, because 856825 - 2⁷ = 856697 is a prime.

It is a Duffinian number.

856825 is a lucky number.

It is an unprimeable number.

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, 17112 + ... + 17161.

2⁸⁵⁶⁸²⁵ is an apocalyptic number.

It is an amenable number.

856825 is a deficient number, since it is larger than the sum of its proper divisors (205669).

856825 is a wasteful number, since it uses less digits than its factorization.

856825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34283 (or 34278 counting only the distinct ones).

The product of its digits is 19200, while the sum is 34.

The square root of 856825 is about 925.6484213782. The cubic root of 856825 is about 94.9796817119.

It can be divided in two parts, 856 and 825, that added together give a square (1681 = 41²).

The spelling of 856825 in words is "eight hundred fifty-six thousand, eight hundred twenty-five".