256681825 has 6 divisors (see below), whose sum is σ = 318285494. Its totient is φ = 205345440.

The previous prime is 256681807. The next prime is 256681837. The reversal of 256681825 is 528186652.

It can be written as a sum of positive squares in 3 ways, for example, as 45037521 + 211644304 = 6711^2 + 14548^2 .

It is not a de Polignac number, because 256681825 - 2¹¹ = 256679777 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5133612 + ... + 5133661.

Almost surely, 2^256681825 is an apocalyptic number.

256681825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

256681825 is a deficient number, since it is larger than the sum of its proper divisors (61603669).

256681825 is a wasteful number, since it uses less digits than its factorization.

256681825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10267283 (or 10267278 counting only the distinct ones).

The product of its digits is 230400, while the sum is 43.

The square root of 256681825 is about 16021.2928629371. The cubic root of 256681825 is about 635.5236344627.

The spelling of 256681825 in words is "two hundred fifty-six million, six hundred eighty-one thousand, eight hundred twenty-five".