205317408505 has 16 divisors (see below), whose sum is σ = 282925425600. Its totient is φ = 141462711360.

The previous prime is 205317408503. The next prime is 205317408551. The reversal of 205317408505 is 505804713502.

It is not a de Polignac number, because 205317408505 - 2¹ = 205317408503 is a prime.

It is not an unprimeable number, because it can be changed into a prime (205317408503) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 98236950 + ... + 98239039.

It is an arithmetic number, because the mean of its divisors is an integer number (17682839100).

Almost surely, 2^205317408505 is an apocalyptic number.

It is an amenable number.

205317408505 is a deficient number, since it is larger than the sum of its proper divisors (77608017095).

205317408505 is a wasteful number, since it uses less digits than its factorization.

205317408505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196476024.

The product of its (nonzero) digits is 168000, while the sum is 40.

The spelling of 205317408505 in words is "two hundred five billion, three hundred seventeen million, four hundred eight thousand, five hundred five".