256787407 has 2 divisors, whose sum is σ = 256787408. Its totient is φ = 256787406.

The previous prime is 256787393. The next prime is 256787417. The reversal of 256787407 is 704787652.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 256787407 - 2¹¹ = 256785359 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256787417) 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 as a sum of consecutive naturals, namely, 128393703 + 128393704.

It is an arithmetic number, because the mean of its divisors is an integer number (128393704).

Almost surely, 2^256787407 is an apocalyptic number.

256787407 is a deficient number, since it is larger than the sum of its proper divisors (1).

256787407 is an equidigital number, since it uses as much as digits as its factorization.

256787407 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 658560, while the sum is 46.

The square root of 256787407 is about 16024.5875765962. The cubic root of 256787407 is about 635.6107600423.

The spelling of 256787407 in words is "two hundred fifty-six million, seven hundred eighty-seven thousand, four hundred seven".