200006561 has 2 divisors, whose sum is σ = 200006562. Its totient is φ = 200006560.

The previous prime is 200006557. The next prime is 200006567. The reversal of 200006561 is 165600002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 111175936 + 88830625 = 10544^2 + 9425^2 .

It is a cyclic number.

It is not a de Polignac number, because 200006561 - 2² = 200006557 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (200006567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100003280 + 100003281.

It is an arithmetic number, because the mean of its divisors is an integer number (100003281).

Almost surely, 2^200006561 is an apocalyptic number.

It is an amenable number.

200006561 is a deficient number, since it is larger than the sum of its proper divisors (1).

200006561 is an equidigital number, since it uses as much as digits as its factorization.

200006561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 200006561 is about 14142.3675882081. The cubic root of 200006561 is about 584.8099423994.

Adding to 200006561 its reverse (165600002), we get a palindrome (365606563).

The spelling of 200006561 in words is "two hundred million, six thousand, five hundred sixty-one".