256718833920 has 720 divisors, whose sum is σ = 951979754880. Its totient is φ = 66012807168.

The previous prime is 256718833901. The next prime is 256718833993. The reversal of 256718833920 is 29338817652.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 396783037 + ... + 396783683.

It is an arithmetic number, because the mean of its divisors is an integer number (1322194104).

Almost surely, 2^256718833920 is an apocalyptic number.

256718833920 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 256718833920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (475989877440).

256718833920 is an abundant number, since it is smaller than the sum of its proper divisors (695260920960).

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

256718833920 is an equidigital number, since it uses as much as digits as its factorization.

256718833920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 812 (or 789 counting only the distinct ones).

The product of its (nonzero) digits is 4354560, while the sum is 54.

The spelling of 256718833920 in words is "two hundred fifty-six billion, seven hundred eighteen million, eight hundred thirty-three thousand, nine hundred twenty".