206268566557 has 2 divisors, whose sum is σ = 206268566558. Its totient is φ = 206268566556.

The previous prime is 206268566509. The next prime is 206268566561. The reversal of 206268566557 is 755665862602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 201434006596 + 4834559961 = 448814^2 + 69531^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-206268566557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (206268566057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103134283278 + 103134283279.

It is an arithmetic number, because the mean of its divisors is an integer number (103134283279).

Almost surely, 2^206268566557 is an apocalyptic number.

It is an amenable number.

206268566557 is a deficient number, since it is larger than the sum of its proper divisors (1).

206268566557 is an equidigital number, since it uses as much as digits as its factorization.

206268566557 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36288000, while the sum is 58.

The spelling of 206268566557 in words is "two hundred six billion, two hundred sixty-eight million, five hundred sixty-six thousand, five hundred fifty-seven".