256780 has 24 divisors (see below), whose sum is σ = 555408. Its totient is φ = 99648.

The previous prime is 256771. The next prime is 256799. The reversal of 256780 is 87652.

It is an unprimeable number.

256780 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 567 + ... + 913.

It is an arithmetic number, because the mean of its divisors is an integer number (23142).

2²⁵⁶⁷⁸⁰ is an apocalyptic number.

256780 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 256780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (277704).

256780 is an abundant number, since it is smaller than the sum of its proper divisors (298628).

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

256780 is a wasteful number, since it uses less digits than its factorization.

256780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393 (or 391 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 256780 is about 506.7346445626. The cubic root of 256780 is about 63.5604648613.

The spelling of 256780 in words is "two hundred fifty-six thousand, seven hundred eighty".