205217101 has 2 divisors, whose sum is σ = 205217102. Its totient is φ = 205217100.

The previous prime is 205217099. The next prime is 205217143. The reversal of 205217101 is 101712502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 165148201 + 40068900 = 12851^2 + 6330^2 .

It is a cyclic number.

It is not a de Polignac number, because 205217101 - 2¹ = 205217099 is a prime.

It is a super-2 number, since 2×205217101² = 84228117085688402, which contains 22 as substring.

Together with 205217099, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205217171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102608550 + 102608551.

It is an arithmetic number, because the mean of its divisors is an integer number (102608551).

Almost surely, 2^205217101 is an apocalyptic number.

It is an amenable number.

205217101 is a deficient number, since it is larger than the sum of its proper divisors (1).

205217101 is an equidigital number, since it uses as much as digits as its factorization.

205217101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 140, while the sum is 19.

The square root of 205217101 is about 14325.4005528641. The cubic root of 205217101 is about 589.8449281241.

Adding to 205217101 its reverse (101712502), we get a palindrome (306929603).

The spelling of 205217101 in words is "two hundred five million, two hundred seventeen thousand, one hundred one".