1211315305 has 4 divisors (see below), whose sum is σ = 1453578372. Its totient is φ = 969052240.

The previous prime is 1211315291. The next prime is 1211315327. The reversal of 1211315305 is 5035131121.

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 500506384 + 710808921 = 22372^2 + 26661^2 .

It is not a de Polignac number, because 1211315305 - 2²⁵ = 1177760873 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121131526 + ... + 121131535.

It is an arithmetic number, because the mean of its divisors is an integer number (363394593).

Almost surely, 2^1211315305 is an apocalyptic number.

It is an amenable number.

1211315305 is a deficient number, since it is larger than the sum of its proper divisors (242263067).

1211315305 is an equidigital number, since it uses as much as digits as its factorization.

1211315305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242263066.

The product of its (nonzero) digits is 450, while the sum is 22.

The square root of 1211315305 is about 34803.9553068326. The cubic root of 1211315305 is about 1065.9882104304.

Adding to 1211315305 its reverse (5035131121), we get a palindrome (6246446426).

The spelling of 1211315305 in words is "one billion, two hundred eleven million, three hundred fifteen thousand, three hundred five".