256781600 has 144 divisors (see below), whose sum is σ = 674956800. Its totient is φ = 95047680.

The previous prime is 256781597. The next prime is 256781621. The reversal of 256781600 is 6187652.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 1074281 + ... + 1074519.

It is an arithmetic number, because the mean of its divisors is an integer number (4687200).

Almost surely, 2^256781600 is an apocalyptic number.

256781600 is a gapful number since it is divisible by the number (20) 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 256781600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (337478400).

256781600 is an abundant number, since it is smaller than the sum of its proper divisors (418175200).

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

256781600 is a wasteful number, since it uses less digits than its factorization.

256781600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 355 (or 342 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 256781600 is about 16024.4063852612. The cubic root of 256781600 is about 635.6059687644.

The spelling of 256781600 in words is "two hundred fifty-six million, seven hundred eighty-one thousand, six hundred".