781856 has 24 divisors (see below), whose sum is σ = 1571724. Its totient is φ = 382720.

The previous prime is 781853. The next prime is 781861. The reversal of 781856 is 658187.

It is a happy number.

781856 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 781456 + 400 = 884^2 + 20^2 .

It is a super-2 number, since 2×781856² = 1222597609472, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (781853) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1466 + ... + 1926.

2⁷⁸¹⁸⁵⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 781856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (785862).

781856 is an abundant number, since it is smaller than the sum of its proper divisors (789868).

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

781856 is a wasteful number, since it uses less digits than its factorization.

781856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 524 (or 516 counting only the distinct ones).

The product of its digits is 13440, while the sum is 35.

The square root of 781856 is about 884.2262153997. The cubic root of 781856 is about 92.1245948910.

The spelling of 781856 in words is "seven hundred eighty-one thousand, eight hundred fifty-six".