856720 has 20 divisors (see below), whose sum is σ = 1992060. Its totient is φ = 342656.

The previous prime is 856717. The next prime is 856721. The reversal of 856720 is 27658.

It can be written as a sum of positive squares in 2 ways, for example, as 614656 + 242064 = 784^2 + 492^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (856721) 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 3 ways as a sum of consecutive naturals, for example, 5275 + ... + 5434.

It is an arithmetic number, because the mean of its divisors is an integer number (99603).

2⁸⁵⁶⁷²⁰ is an apocalyptic number.

856720 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

856720 is an abundant number, since it is smaller than the sum of its proper divisors (1135340).

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

856720 is a wasteful number, since it uses less digits than its factorization.

856720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10722 (or 10716 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 856720 is about 925.5917026422. The cubic root of 856720 is about 94.9758017777.

The spelling of 856720 in words is "eight hundred fifty-six thousand, seven hundred twenty".