256981760 has 288 divisors, whose sum is σ = 777047040. Its totient is φ = 79478784.

The previous prime is 256981733. The next prime is 256981787. The reversal of 256981760 is 67189652.

It is an interprime number because it is at equal distance from previous prime (256981733) and next prime (256981787).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5976299 + ... + 5976341.

It is an arithmetic number, because the mean of its divisors is an integer number (2698080).

Almost surely, 2^256981760 is an apocalyptic number.

256981760 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 256981760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (388523520).

256981760 is an abundant number, since it is smaller than the sum of its proper divisors (520065280).

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

256981760 is a wasteful number, since it uses less digits than its factorization.

256981760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123 (or 109 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 44.

The square root of 256981760 is about 16030.6506418174. The cubic root of 256981760 is about 635.7710764518.

The spelling of 256981760 in words is "two hundred fifty-six million, nine hundred eighty-one thousand, seven hundred sixty".