1256791680 has 256 divisors, whose sum is σ = 4484246400. Its totient is φ = 332660736.

The previous prime is 1256791663. The next prime is 1256791681. The reversal of 1256791680 is 861976521.

1256791680 is a `hidden beast` number, since 1 + 2 + 567 + 9 + 1 + 6 + 80 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (1256791681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4440819 + ... + 4441101.

Almost surely, 2^1256791680 is an apocalyptic number.

1256791680 is a gapful number since it is divisible by the number (10) 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 1256791680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2242123200).

1256791680 is an abundant number, since it is smaller than the sum of its proper divisors (3227454720).

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

1256791680 is a wasteful number, since it uses less digits than its factorization.

1256791680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 568 (or 550 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 45.

The square root of 1256791680 is about 35451.2578056125. The cubic root of 1256791680 is about 1079.1647863562.

The spelling of 1256791680 in words is "one billion, two hundred fifty-six million, seven hundred ninety-one thousand, six hundred eighty".