856240 has 80 divisors (see below), whose sum is σ = 2499840. Its totient is φ = 264960.

The previous prime is 856237. The next prime is 856241. The reversal of 856240 is 42658.

856240 = T₂₇₅ + T₂₇₆ + ... + T₂₉₅.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (856241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6091 + ... + 6229.

It is an arithmetic number, because the mean of its divisors is an integer number (31248).

2⁸⁵⁶²⁴⁰ is an apocalyptic number.

856240 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 856240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1249920).

856240 is an abundant number, since it is smaller than the sum of its proper divisors (1643600).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

856240 is a wasteful number, since it uses less digits than its factorization.

856240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170 (or 164 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 856240 is about 925.3323727180. The cubic root of 856240 is about 94.9580608972.

Adding to 856240 its reverse (42658), we get a palindrome (898898).

The spelling of 856240 in words is "eight hundred fifty-six thousand, two hundred forty".