256681617 has 16 divisors (see below), whose sum is σ = 358977792. Its totient is φ = 162950400.

The previous prime is 256681609. The next prime is 256681631. The reversal of 256681617 is 716186652.

256681617 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 256681617 - 2³ = 256681609 is a prime.

It is not an unprimeable number, because it can be changed into a prime (256681637) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19384 + ... + 29817.

It is an arithmetic number, because the mean of its divisors is an integer number (22436112).

Almost surely, 2^256681617 is an apocalyptic number.

It is an amenable number.

256681617 is a deficient number, since it is larger than the sum of its proper divisors (102296175).

256681617 is a wasteful number, since it uses less digits than its factorization.

256681617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49288.

The product of its digits is 120960, while the sum is 42.

The square root of 256681617 is about 16021.2863715745. The cubic root of 256681617 is about 635.5234627989.

The spelling of 256681617 in words is "two hundred fifty-six million, six hundred eighty-one thousand, six hundred seventeen".