205235142563021 has 2 divisors, whose sum is σ = 205235142563022. Its totient is φ = 205235142563020.

The previous prime is 205235142562999. The next prime is 205235142563051. The reversal of 205235142563021 is 120365241532502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 202863191430025 + 2371951132996 = 14243005^2 + 1540114^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-205235142563021 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 205235142563021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205235142563051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102617571281510 + 102617571281511.

It is an arithmetic number, because the mean of its divisors is an integer number (102617571281511).

Almost surely, 2^{205235142563021} is an apocalyptic number.

It is an amenable number.

205235142563021 is a deficient number, since it is larger than the sum of its proper divisors (1).

205235142563021 is an equidigital number, since it uses as much as digits as its factorization.

205235142563021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432000, while the sum is 41.

The spelling of 205235142563021 in words is "two hundred five trillion, two hundred thirty-five billion, one hundred forty-two million, five hundred sixty-three thousand, twenty-one".