205212005 has 4 divisors (see below), whose sum is σ = 246254412. Its totient is φ = 164169600.

The previous prime is 205211999. The next prime is 205212037. The reversal of 205212005 is 500212502.

205212005 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 22448644 + 182763361 = 4738^2 + 13519^2 .

It is a de Polignac number, because none of the positive numbers 2^k-205212005 is a prime.

It is a super-2 number, since 2×205212005² = 84223933992240050, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20521196 + ... + 20521205.

It is an arithmetic number, because the mean of its divisors is an integer number (61563603).

Almost surely, 2^205212005 is an apocalyptic number.

It is an amenable number.

205212005 is a deficient number, since it is larger than the sum of its proper divisors (41042407).

205212005 is an equidigital number, since it uses as much as digits as its factorization.

205212005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41042406.

The product of its (nonzero) digits is 200, while the sum is 17.

The square root of 205212005 is about 14325.2226858782. Note that the first 3 decimals coincide. The cubic root of 205212005 is about 589.8400456937.

Adding to 205212005 its reverse (500212502), we get a palindrome (705424507).

The spelling of 205212005 in words is "two hundred five million, two hundred twelve thousand, five".