256210643 has 4 divisors (see below), whose sum is σ = 275919168. Its totient is φ = 236502120.

The previous prime is 256210637. The next prime is 256210657. The reversal of 256210643 is 346012652.

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 256210643 - 2¹² = 256206547 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256210693) 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, 9854243 + ... + 9854268.

It is an arithmetic number, because the mean of its divisors is an integer number (68979792).

Almost surely, 2^256210643 is an apocalyptic number.

256210643 is a deficient number, since it is larger than the sum of its proper divisors (19708525).

256210643 is a wasteful number, since it uses less digits than its factorization.

256210643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19708524.

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 256210643 is about 16006.5812402274. The cubic root of 256210643 is about 635.1345266472.

The spelling of 256210643 in words is "two hundred fifty-six million, two hundred ten thousand, six hundred forty-three".