256721144 has 48 divisors (see below), whose sum is σ = 501054000. Its totient is φ = 123285888.

The previous prime is 256721117. The next prime is 256721167. The reversal of 256721144 is 441127652.

256721144 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 256721144.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1289957 + ... + 1290155.

It is an arithmetic number, because the mean of its divisors is an integer number (10438625).

Almost surely, 2^256721144 is an apocalyptic number.

It is an amenable number.

256721144 is a deficient number, since it is larger than the sum of its proper divisors (244332856).

256721144 is a wasteful number, since it uses less digits than its factorization.

256721144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 372 (or 321 counting only the distinct ones).

The product of its digits is 13440, while the sum is 32.

The square root of 256721144 is about 16022.5199016884. The cubic root of 256721144 is about 635.5560830372.

Adding to 256721144 its reverse (441127652), we get a palindrome (697848796).

The spelling of 256721144 in words is "two hundred fifty-six million, seven hundred twenty-one thousand, one hundred forty-four".