256726689 has 8 divisors (see below), whose sum is σ = 360318240. Its totient is φ = 162143136.

The previous prime is 256726649. The next prime is 256726777. The reversal of 256726689 is 986627652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 256726689 - 2¹⁷ = 256595617 is a prime.

It is not an unprimeable number, because it can be changed into a prime (256726649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2251932 + ... + 2252045.

It is an arithmetic number, because the mean of its divisors is an integer number (45039780).

Almost surely, 2^256726689 is an apocalyptic number.

It is an amenable number.

256726689 is a deficient number, since it is larger than the sum of its proper divisors (103591551).

256726689 is a wasteful number, since it uses less digits than its factorization.

256726689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4503999.

The product of its digits is 2177280, while the sum is 51.

The square root of 256726689 is about 16022.6929384545. The cubic root of 256726689 is about 635.5606588622.

The spelling of 256726689 in words is "two hundred fifty-six million, seven hundred twenty-six thousand, six hundred eighty-nine".