856040 has 16 divisors (see below), whose sum is σ = 1926180. Its totient is φ = 342400.

The previous prime is 856021. The next prime is 856043. The reversal of 856040 is 40658.

856040 = T₂₅₅ + T₂₅₆ + ... + T₂₇₈.

It can be written as a sum of positive squares in 2 ways, for example, as 813604 + 42436 = 902^2 + 206^2 .

It is a junction number, because it is equal to n+sod(n) for n = 855997 and 856015.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 856040.

It is not an unprimeable number, because it can be changed into a prime (856043) by changing a digit.

856040 is an untouchable number, because it is not equal to the sum of proper divisors of any 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 3 ways as a sum of consecutive naturals, for example, 10661 + ... + 10740.

2⁸⁵⁶⁰⁴⁰ is an apocalyptic number.

It is an amenable number.

856040 is an abundant number, since it is smaller than the sum of its proper divisors (1070140).

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

856040 is a wasteful number, since it uses less digits than its factorization.

856040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21412 (or 21408 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 856040 is about 925.2242971302. The cubic root of 856040 is about 94.9506669067.

Adding to 856040 its reverse (40658), we get a palindrome (896698).

The spelling of 856040 in words is "eight hundred fifty-six thousand, forty".