256809539424 has 96 divisors (see below), whose sum is σ = 687039996384. Its totient is φ = 83964108800.

The previous prime is 256809539419. The next prime is 256809539501. The reversal of 256809539424 is 424935908652.

256809539424 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×256809539424² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31037752 + ... + 31046024.

It is an arithmetic number, because the mean of its divisors is an integer number (7156666629).

Almost surely, 2^256809539424 is an apocalyptic number.

256809539424 is a gapful number since it is divisible by the number (24) 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 256809539424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (343519998192).

256809539424 is an abundant number, since it is smaller than the sum of its proper divisors (430230456960).

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

256809539424 is a wasteful number, since it uses less digits than its factorization.

256809539424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14440 (or 14432 counting only the distinct ones).

The product of its (nonzero) digits is 18662400, while the sum is 57.

The spelling of 256809539424 in words is "two hundred fifty-six billion, eight hundred nine million, five hundred thirty-nine thousand, four hundred twenty-four".