205490105 has 4 divisors (see below), whose sum is σ = 246588132. Its totient is φ = 164392080.

The previous prime is 205490099. The next prime is 205490107. The reversal of 205490105 is 501094502.

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 48664576 + 156825529 = 6976^2 + 12523^2 .

It is not a de Polignac number, because 205490105 - 2²⁰ = 204441529 is a prime.

It is a super-2 number, since 2×205490105² = 84452366505822050, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205490107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20549006 + ... + 20549015.

It is an arithmetic number, because the mean of its divisors is an integer number (61647033).

Almost surely, 2^205490105 is an apocalyptic number.

It is an amenable number.

205490105 is a deficient number, since it is larger than the sum of its proper divisors (41098027).

205490105 is an equidigital number, since it uses as much as digits as its factorization.

205490105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41098026.

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 205490105 is about 14334.9260549192. The cubic root of 205490105 is about 590.1063726621.

The spelling of 205490105 in words is "two hundred five million, four hundred ninety thousand, one hundred five".