256611720 has 128 divisors (see below), whose sum is σ = 838512000. Its totient is φ = 62576640.

The previous prime is 256611703. The next prime is 256611721. The reversal of 256611720 is 27116652.

256611720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (256611721) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 64180 + ... + 68060.

It is an arithmetic number, because the mean of its divisors is an integer number (6550875).

Almost surely, 2^256611720 is an apocalyptic number.

256611720 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 256611720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (419256000).

256611720 is an abundant number, since it is smaller than the sum of its proper divisors (581900280).

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

256611720 is a wasteful number, since it uses less digits than its factorization.

256611720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3943 (or 3939 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 30.

The square root of 256611720 is about 16019.1048439044. The cubic root of 256611720 is about 635.4657710733.

The spelling of 256611720 in words is "two hundred fifty-six million, six hundred eleven thousand, seven hundred twenty".