205511313 has 16 divisors (see below), whose sum is σ = 323959680. Its totient is φ = 113385216.

The previous prime is 205511309. The next prime is 205511329. The reversal of 205511313 is 313115502.

It is not a de Polignac number, because 205511313 - 2² = 205511309 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 205511313.

It is not an unprimeable number, because it can be changed into a prime (205511303) 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, 168120 + ... + 169337.

It is an arithmetic number, because the mean of its divisors is an integer number (20247480).

Almost surely, 2^205511313 is an apocalyptic number.

It is an amenable number.

205511313 is a deficient number, since it is larger than the sum of its proper divisors (118448367).

205511313 is a wasteful number, since it uses less digits than its factorization.

205511313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 337496.

The product of its (nonzero) digits is 450, while the sum is 21.

The square root of 205511313 is about 14335.6657675882. The cubic root of 205511313 is about 590.1266729833.

Adding to 205511313 its reverse (313115502), we get a palindrome (518626815).

The spelling of 205511313 in words is "two hundred five million, five hundred eleven thousand, three hundred thirteen".