256740223 has 4 divisors (see below), whose sum is σ = 257012280. Its totient is φ = 256468168.

The previous prime is 256740221. The next prime is 256740247. The reversal of 256740223 is 322047652.

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

It is a cyclic number.

It is not a de Polignac number, because 256740223 - 2¹ = 256740221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256740221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 134608 + ... + 136501.

It is an arithmetic number, because the mean of its divisors is an integer number (64253070).

Almost surely, 2^256740223 is an apocalyptic number.

256740223 is a deficient number, since it is larger than the sum of its proper divisors (272057).

256740223 is an equidigital number, since it uses as much as digits as its factorization.

256740223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 272056.

The product of its (nonzero) digits is 20160, while the sum is 31.

The square root of 256740223 is about 16023.1152713822. The cubic root of 256740223 is about 635.5718270646.

Adding to 256740223 its reverse (322047652), we get a palindrome (578787875).

The spelling of 256740223 in words is "two hundred fifty-six million, seven hundred forty thousand, two hundred twenty-three".