1256759856 has 120 divisors (see below), whose sum is σ = 3874680576. Its totient is φ = 377089920.

The previous prime is 1256759851. The next prime is 1256759857. The reversal of 1256759856 is 6589576521.

It is not an unprimeable number, because it can be changed into a prime (1256759851) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 159301 + ... + 167003.

Almost surely, 2^1256759856 is an apocalyptic number.

1256759856 is a gapful number since it is divisible by the number (16) 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 1256759856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1937340288).

1256759856 is an abundant number, since it is smaller than the sum of its proper divisors (2617920720).

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

1256759856 is a wasteful number, since it uses less digits than its factorization.

1256759856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7831 (or 7822 counting only the distinct ones).

The product of its digits is 4536000, while the sum is 54.

The square root of 1256759856 is about 35450.8089611507. The cubic root of 1256759856 is about 1079.1556775461.

It can be divided in two parts, 125675 and 9856, that added together give a palindrome (135531).

The spelling of 1256759856 in words is "one billion, two hundred fifty-six million, seven hundred fifty-nine thousand, eight hundred fifty-six".