256241209 has 4 divisors (see below), whose sum is σ = 292847104. Its totient is φ = 219635316.

The previous prime is 256241203. The next prime is 256241213. The reversal of 256241209 is 902142652.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 256241209 - 2⁵ = 256241177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256241203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18302937 + ... + 18302950.

It is an arithmetic number, because the mean of its divisors is an integer number (73211776).

Almost surely, 2^256241209 is an apocalyptic number.

It is an amenable number.

256241209 is a deficient number, since it is larger than the sum of its proper divisors (36605895).

256241209 is an equidigital number, since it uses as much as digits as its factorization.

256241209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36605894.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 256241209 is about 16007.5360065189. The cubic root of 256241209 is about 635.1597828840.

The spelling of 256241209 in words is "two hundred fifty-six million, two hundred forty-one thousand, two hundred nine".