256721068800 has 2592 divisors, whose sum is σ = 1214642257920. Its totient is φ = 50363596800.

The previous prime is 256721068787. The next prime is 256721068841. The reversal of 256721068800 is 8860127652.

256721068800 is a `hidden beast` number, since 2 + 567 + 2 + 1 + 0 + 6 + 8 + 80 + 0 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 5462150377 + ... + 5462150423.

Almost surely, 2^256721068800 is an apocalyptic number.

256721068800 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 256721068800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (607321128960).

256721068800 is an abundant number, since it is smaller than the sum of its proper divisors (957921189120).

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

256721068800 is a wasteful number, since it uses less digits than its factorization.

256721068800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159 (or 137 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 45.

The spelling of 256721068800 in words is "two hundred fifty-six billion, seven hundred twenty-one million, sixty-eight thousand, eight hundred".