256743251 has 8 divisors (see below), whose sum is σ = 259048608. Its totient is φ = 254448000.

The previous prime is 256743247. The next prime is 256743269. The reversal of 256743251 is 152347652.

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

It is a cyclic number.

It is not a de Polignac number, because 256743251 - 2² = 256743247 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256743451) 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 7 ways as a sum of consecutive naturals, for example, 54011 + ... + 58571.

It is an arithmetic number, because the mean of its divisors is an integer number (32381076).

Almost surely, 2^256743251 is an apocalyptic number.

256743251 is a deficient number, since it is larger than the sum of its proper divisors (2305357).

256743251 is a wasteful number, since it uses less digits than its factorization.

256743251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5053.

The product of its digits is 50400, while the sum is 35.

The square root of 256743251 is about 16023.2097595956. The cubic root of 256743251 is about 635.5743257042.

The spelling of 256743251 in words is "two hundred fifty-six million, seven hundred forty-three thousand, two hundred fifty-one".