199539765845657 has 2 divisors, whose sum is σ = 199539765845658. Its totient is φ = 199539765845656.

The previous prime is 199539765845621. The next prime is 199539765845669. The reversal of 199539765845657 is 756548567935991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 144302823037321 + 55236942808336 = 12012611^2 + 7432156^2 .

It is a cyclic number.

It is not a de Polignac number, because 199539765845657 - 2²⁴ = 199539749068441 is a prime.

It is a super-2 number, since 2×199539765845657² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (199539765845687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99769882922828 + 99769882922829.

It is an arithmetic number, because the mean of its divisors is an integer number (99769882922829).

Almost surely, 2^{199539765845657} is an apocalyptic number.

It is an amenable number.

199539765845657 is a deficient number, since it is larger than the sum of its proper divisors (1).

199539765845657 is an equidigital number, since it uses as much as digits as its factorization.

199539765845657 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 77157360000, while the sum is 89.

The spelling of 199539765845657 in words is "one hundred ninety-nine trillion, five hundred thirty-nine billion, seven hundred sixty-five million, eight hundred forty-five thousand, six hundred fifty-seven".