256195649 has 4 divisors (see below), whose sum is σ = 256234836. Its totient is φ = 256156464.

The previous prime is 256195631. The next prime is 256195663. The reversal of 256195649 is 946591652.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 75777025 + 180418624 = 8705^2 + 13432^2 .

It is a cyclic number.

It is not a de Polignac number, because 256195649 - 2⁸ = 256195393 is a prime.

It is a super-3 number, since 3×256195649³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256195609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7154 + ... + 23739.

It is an arithmetic number, because the mean of its divisors is an integer number (64058709).

Almost surely, 2^256195649 is an apocalyptic number.

It is an amenable number.

256195649 is a deficient number, since it is larger than the sum of its proper divisors (39187).

256195649 is an equidigital number, since it uses as much as digits as its factorization.

256195649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39186.

The product of its digits is 583200, while the sum is 47.

The square root of 256195649 is about 16006.1128635281. The cubic root of 256195649 is about 635.1221365909.

The spelling of 256195649 in words is "two hundred fifty-six million, one hundred ninety-five thousand, six hundred forty-nine".