256506347 has 2 divisors, whose sum is σ = 256506348. Its totient is φ = 256506346.

The previous prime is 256506343. The next prime is 256506361. The reversal of 256506347 is 743605652.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 256506347 - 2² = 256506343 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 256506347.

It is not a weakly prime, because it can be changed into another prime (256506343) 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 as a sum of consecutive naturals, namely, 128253173 + 128253174.

It is an arithmetic number, because the mean of its divisors is an integer number (128253174).

Almost surely, 2^256506347 is an apocalyptic number.

256506347 is a deficient number, since it is larger than the sum of its proper divisors (1).

256506347 is an equidigital number, since it uses as much as digits as its factorization.

256506347 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 151200, while the sum is 38.

The square root of 256506347 is about 16015.8155271594. The cubic root of 256506347 is about 635.3787782914.

The spelling of 256506347 in words is "two hundred fifty-six million, five hundred six thousand, three hundred forty-seven".