20205235117 has 2 divisors, whose sum is σ = 20205235118. Its totient is φ = 20205235116.

The previous prime is 20205235079. The next prime is 20205235123. The reversal of 20205235117 is 71153250202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17289883081 + 2915352036 = 131491^2 + 53994^2 .

It is a cyclic number.

It is not a de Polignac number, because 20205235117 - 2¹⁹ = 20204710829 is a prime.

It is a super-2 number, since 2×20205235117² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20205235147) 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 as a sum of consecutive naturals, namely, 10102617558 + 10102617559.

It is an arithmetic number, because the mean of its divisors is an integer number (10102617559).

Almost surely, 2^20205235117 is an apocalyptic number.

It is an amenable number.

20205235117 is a deficient number, since it is larger than the sum of its proper divisors (1).

20205235117 is an equidigital number, since it uses as much as digits as its factorization.

20205235117 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4200, while the sum is 28.

Adding to 20205235117 its reverse (71153250202), we get a palindrome (91358485319).

It can be divided in two parts, 202052 and 35117, that added together give a square (237169 = 487²).

The spelling of 20205235117 in words is "twenty billion, two hundred five million, two hundred thirty-five thousand, one hundred seventeen".