205909012445 has 6 divisors (see below), whose sum is σ = 247092032538. Its totient is φ = 164726398224.

The previous prime is 205909012429. The next prime is 205909012447. The reversal of 205909012445 is 544210909502.

It can be written as a sum of positive squares in 3 ways, for example, as 89210937124 + 116698075321 = 298682^2 + 341611^2 .

It is not a de Polignac number, because 205909012445 - 2⁴ = 205909012429 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 (205909012447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 913199 + ... + 1116131.

It is an arithmetic number, because the mean of its divisors is an integer number (41182005423).

Almost surely, 2^205909012445 is an apocalyptic number.

It is an amenable number.

205909012445 is a deficient number, since it is larger than the sum of its proper divisors (41183020093).

205909012445 is an frugal number, since it uses more digits than its factorization.

205909012445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 405871 (or 202938 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 41.

The spelling of 205909012445 in words is "two hundred five billion, nine hundred nine million, twelve thousand, four hundred forty-five".