256761123840 has 1056 divisors, whose sum is σ = 1068663697920. Its totient is φ = 56311676928.

The previous prime is 256761123779. The next prime is 256761123851. The reversal of 256761123840 is 48321167652.

256761123840 is a `hidden beast` number, since 2 + 5 + 6 + 7 + 611 + 23 + 8 + 4 + 0 = 666.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

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 95 ways as a sum of consecutive naturals, for example, 193489257 + ... + 193490583.

Almost surely, 2^256761123840 is an apocalyptic number.

256761123840 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 256761123840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (534331848960).

256761123840 is an abundant number, since it is smaller than the sum of its proper divisors (811902574080).

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

256761123840 is a wasteful number, since it uses less digits than its factorization.

256761123840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1407 (or 1386 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 45.

The spelling of 256761123840 in words is "two hundred fifty-six billion, seven hundred sixty-one million, one hundred twenty-three thousand, eight hundred forty".