256038643 has 4 divisors (see below), whose sum is σ = 292615600. Its totient is φ = 219461688.

The previous prime is 256038637. The next prime is 256038647. The reversal of 256038643 is 346830652.

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 256038643 - 2⁵ = 256038611 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256038647) 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, 18288468 + ... + 18288481.

It is an arithmetic number, because the mean of its divisors is an integer number (73153900).

Almost surely, 2^256038643 is an apocalyptic number.

256038643 is a deficient number, since it is larger than the sum of its proper divisors (36576957).

256038643 is an equidigital number, since it uses as much as digits as its factorization.

256038643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36576956.

The product of its (nonzero) digits is 103680, while the sum is 37.

The square root of 256038643 is about 16001.2075481821. The cubic root of 256038643 is about 634.9923681063.

The spelling of 256038643 in words is "two hundred fifty-six million, thirty-eight thousand, six hundred forty-three".