256181512320 has 320 divisors, whose sum is σ = 932142138840. Its totient is φ = 67025387520.

The previous prime is 256181512319. The next prime is 256181512381. The reversal of 256181512320 is 23215181652.

256181512320 is a `hidden beast` number, since 2 + 5 + 61 + 81 + 512 + 3 + 2 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 245595571776 + 10585940544 = 495576^2 + 102888^2 .

It is a tau number, because it is divible by the number of its divisors (320).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 2700900 + ... + 2794140.

Almost surely, 2^256181512320 is an apocalyptic number.

256181512320 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 256181512320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (466071069420).

256181512320 is an abundant number, since it is smaller than the sum of its proper divisors (675960626520).

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

256181512320 is an equidigital number, since it uses as much as digits as its factorization.

256181512320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93325 (or 93304 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 36.

Adding to 256181512320 its reverse (23215181652), we get a palindrome (279396693972).

The spelling of 256181512320 in words is "two hundred fifty-six billion, one hundred eighty-one million, five hundred twelve thousand, three hundred twenty".