256718730240 has 792 divisors, whose sum is σ = 1073331054432. Its totient is φ = 58664632320.

The previous prime is 256718730239. The next prime is 256718730251. The reversal of 256718730240 is 42037817652.

256718730240 is a `hidden beast` number, since 2 + 567 + 1 + 87 + 3 + 0 + 2 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

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, 60961735 + ... + 60965945.

Almost surely, 2^256718730240 is an apocalyptic number.

256718730240 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 256718730240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (536665527216).

256718730240 is an abundant number, since it is smaller than the sum of its proper divisors (816612324192).

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

256718730240 is an equidigital number, since it uses as much as digits as its factorization.

256718730240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4265 (or 4228 counting only the distinct ones).

The product of its (nonzero) digits is 564480, while the sum is 45.

The spelling of 256718730240 in words is "two hundred fifty-six billion, seven hundred eighteen million, seven hundred thirty thousand, two hundred forty".