256781373696 has 729 divisors, whose sum is σ = 853736086021. Its totient is φ = 77056303104.

The previous prime is 256781373677. The next prime is 256781373703. The reversal of 256781373696 is 696373187652.

The square root of 256781373696 is 506736.

It is a perfect power (a square), and thus also a powerful number.

256781373696 is a `hidden beast` number, since 2 + 567 + 8 + 1 + 3 + 7 + 3 + 69 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 199916294400 + 56865079296 = 447120^2 + 238464^2 .

It is a tau number, because it is divible by the number of its divisors (729).

It is a Duffinian number.

Its product of digits (68584320) is a multiple of the sum of its prime divisors (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 11164407541 + ... + 11164407563.

Almost surely, 2^256781373696 is an apocalyptic number.

256781373696 is the 506736-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256781373696

256781373696 is an abundant number, since it is smaller than the sum of its proper divisors (596954712325).

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

256781373696 is an frugal number, since it uses more digits than its factorization.

256781373696 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120 (or 45 counting only the distinct ones).

The product of its digits is 68584320, while the sum is 63.

The spelling of 256781373696 in words is "two hundred fifty-six billion, seven hundred eighty-one million, three hundred seventy-three thousand, six hundred ninety-six".