256515265290240 has 2688 divisors, whose sum is σ = 1042018942648320. Its totient is φ = 59996779315200.

The previous prime is 256515265290223. The next prime is 256515265290253. The reversal of 256515265290240 is 42092562515652.

256515265290240 is a `hidden beast` number, since 2 + 5 + 6 + 5 + 1 + 52 + 65 + 290 + 240 = 666.

It is a super-2 number, since 2×256515265290240² (a number of 30 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 406521814725 + ... + 406521815355.

It is an arithmetic number, because the mean of its divisors is an integer number (387655856640).

Almost surely, 2^{256515265290240} is an apocalyptic number.

256515265290240 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 256515265290240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (521009471324160).

256515265290240 is an abundant number, since it is smaller than the sum of its proper divisors (785503677358080).

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

256515265290240 is an equidigital number, since it uses as much as digits as its factorization.

256515265290240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 814 (or 778 counting only the distinct ones).

The product of its (nonzero) digits is 12960000, while the sum is 54.

The spelling of 256515265290240 in words is "two hundred fifty-six trillion, five hundred fifteen billion, two hundred sixty-five million, two hundred ninety thousand, two hundred forty".