205520101 has 4 divisors (see below), whose sum is σ = 205627500. Its totient is φ = 205412704.

The previous prime is 205520087. The next prime is 205520113. The reversal of 205520101 is 101025502.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 125417601 + 80102500 = 11199^2 + 8950^2 .

It is a cyclic number.

It is not a de Polignac number, because 205520101 - 2¹³ = 205511909 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205520141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50776 + ... + 54673.

It is an arithmetic number, because the mean of its divisors is an integer number (51406875).

Almost surely, 2^205520101 is an apocalyptic number.

It is an amenable number.

205520101 is a deficient number, since it is larger than the sum of its proper divisors (107399).

205520101 is a wasteful number, since it uses less digits than its factorization.

205520101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107398.

The product of its (nonzero) digits is 100, while the sum is 16.

The square root of 205520101 is about 14335.9722725736. The cubic root of 205520101 is about 590.1350844574.

Adding to 205520101 its reverse (101025502), we get a palindrome (306545603).

The spelling of 205520101 in words is "two hundred five million, five hundred twenty thousand, one hundred one".