1311105205 has 4 divisors (see below), whose sum is σ = 1573326252. Its totient is φ = 1048884160.

The previous prime is 1311105199. The next prime is 1311105209. The reversal of 1311105205 is 5025011131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5025011131 = 7 ⋅717858733.

It can be written as a sum of positive squares in 2 ways, for example, as 878173956 + 432931249 = 29634^2 + 20807^2 .

It is not a de Polignac number, because 1311105205 - 2³ = 1311105197 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 (1311105209) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 131110516 + ... + 131110525.

It is an arithmetic number, because the mean of its divisors is an integer number (393331563).

Almost surely, 2^1311105205 is an apocalyptic number.

It is an amenable number.

1311105205 is a deficient number, since it is larger than the sum of its proper divisors (262221047).

1311105205 is an equidigital number, since it uses as much as digits as its factorization.

1311105205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 262221046.

The product of its (nonzero) digits is 150, while the sum is 19.

The square root of 1311105205 is about 36209.1867486692. The cubic root of 1311105205 is about 1094.4918042403.

Adding to 1311105205 its reverse (5025011131), we get a palindrome (6336116336).

The spelling of 1311105205 in words is "one billion, three hundred eleven million, one hundred five thousand, two hundred five".