1312211305 has 4 divisors (see below), whose sum is σ = 1574653572. Its totient is φ = 1049769040.

The previous prime is 1312211293. The next prime is 1312211309. The reversal of 1312211305 is 5031122131.

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 390299536 + 921911769 = 19756^2 + 30363^2 .

It is not a de Polignac number, because 1312211305 - 2⁹ = 1312210793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1312211309) 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, 131221126 + ... + 131221135.

It is an arithmetic number, because the mean of its divisors is an integer number (393663393).

Almost surely, 2^1312211305 is an apocalyptic number.

It is an amenable number.

1312211305 is a deficient number, since it is larger than the sum of its proper divisors (262442267).

1312211305 is an equidigital number, since it uses as much as digits as its factorization.

1312211305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 262442266.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 1312211305 is about 36224.4572768178. The cubic root of 1312211305 is about 1094.7995031948.

Adding to 1312211305 its reverse (5031122131), we get a palindrome (6343333436).

The spelling of 1312211305 in words is "one billion, three hundred twelve million, two hundred eleven thousand, three hundred five".