205112521 has 2 divisors, whose sum is σ = 205112522. Its totient is φ = 205112520.

The previous prime is 205112483. The next prime is 205112549. The reversal of 205112521 is 125211502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 204490000 + 622521 = 14300^2 + 789^2 .

It is a cyclic number.

It is not a de Polignac number, because 205112521 - 2¹⁷ = 204981449 is a prime.

It is a super-2 number, since 2×205112521² = 84142292541950882, which contains 22 as substring.

It is equal to p_11346301 and since 205112521 and 11346301 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (205113521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102556260 + 102556261.

It is an arithmetic number, because the mean of its divisors is an integer number (102556261).

Almost surely, 2^205112521 is an apocalyptic number.

It is an amenable number.

205112521 is a deficient number, since it is larger than the sum of its proper divisors (1).

205112521 is an equidigital number, since it uses as much as digits as its factorization.

205112521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 200, while the sum is 19.

The square root of 205112521 is about 14321.7499279941. The cubic root of 205112521 is about 589.7447147992.

It can be divided in two parts, 20511 and 2521, that added together give a palindrome (23032).

The spelling of 205112521 in words is "two hundred five million, one hundred twelve thousand, five hundred twenty-one".