256566733 has 2 divisors, whose sum is σ = 256566734. Its totient is φ = 256566732.

The previous prime is 256566677. The next prime is 256566763. The reversal of 256566733 is 337665652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 191490244 + 65076489 = 13838^2 + 8067^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256566733 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 256566733.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256566763) 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, 128283366 + 128283367.

It is an arithmetic number, because the mean of its divisors is an integer number (128283367).

Almost surely, 2^256566733 is an apocalyptic number.

It is an amenable number.

256566733 is a deficient number, since it is larger than the sum of its proper divisors (1).

256566733 is an equidigital number, since it uses as much as digits as its factorization.

256566733 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 680400, while the sum is 43.

The square root of 256566733 is about 16017.7006152569. The cubic root of 256566733 is about 635.4286340720.

The spelling of 256566733 in words is "two hundred fifty-six million, five hundred sixty-six thousand, seven hundred thirty-three".