256749843456 has 528 divisors, whose sum is σ = 838652690304. Its totient is φ = 75209637888.

The previous prime is 256749843431. The next prime is 256749843461. The reversal of 256749843456 is 654348947652.

256749843456 is a `hidden beast` number, since 2 + 5 + 67 + 4 + 98 + 434 + 56 = 666.

It is a super-2 number, since 2×256749843456² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 256749843393 and 256749843402.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 154947780 + ... + 154949436.

It is an arithmetic number, because the mean of its divisors is an integer number (1588357368).

Almost surely, 2^256749843456 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256749843456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (419326345152).

256749843456 is an abundant number, since it is smaller than the sum of its proper divisors (581902846848).

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

256749843456 is a wasteful number, since it uses less digits than its factorization.

256749843456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1766 (or 1745 counting only the distinct ones).

The product of its digits is 174182400, while the sum is 63.

The spelling of 256749843456 in words is "two hundred fifty-six billion, seven hundred forty-nine million, eight hundred forty-three thousand, four hundred fifty-six".