256520811456 has 504 divisors, whose sum is σ = 919538159904. Its totient is φ = 66939125760.

The previous prime is 256520811439. The next prime is 256520811499. The reversal of 256520811456 is 654118025652.

256520811456 is a `hidden beast` number, since 2 + 5 + 6 + 520 + 8 + 114 + 5 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (504).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 66094636 + ... + 66098516.

It is an arithmetic number, because the mean of its divisors is an integer number (1824480476).

Almost surely, 2^256520811456 is an apocalyptic number.

256520811456 is a gapful number since it is divisible by the number (26) 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 256520811456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (459769079952).

256520811456 is an abundant number, since it is smaller than the sum of its proper divisors (663017348448).

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

256520811456 is a wasteful number, since it uses less digits than its factorization.

256520811456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4029 (or 4003 counting only the distinct ones).

The product of its (nonzero) digits is 576000, while the sum is 45.

The spelling of 256520811456 in words is "two hundred fifty-six billion, five hundred twenty million, eight hundred eleven thousand, four hundred fifty-six".