1312231221305 has 4 divisors (see below), whose sum is σ = 1574677465572. Its totient is φ = 1049784977040.

The previous prime is 1312231221289. The next prime is 1312231221313. The reversal of 1312231221305 is 5031221322131.

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 382898588944 + 929332632361 = 618788^2 + 964019^2 .

It is not a de Polignac number, because 1312231221305 - 2⁴ = 1312231221289 is a prime.

It is a super-2 number, since 2×1312231221305² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 131223122126 + ... + 131223122135.

It is an arithmetic number, because the mean of its divisors is an integer number (393669366393).

Almost surely, 2^{1312231221305} is an apocalyptic number.

It is an amenable number.

1312231221305 is a deficient number, since it is larger than the sum of its proper divisors (262446244267).

1312231221305 is an equidigital number, since it uses as much as digits as its factorization.

1312231221305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262446244266.

The product of its (nonzero) digits is 2160, while the sum is 26.

Adding to 1312231221305 its reverse (5031221322131), we get a palindrome (6343452543436).

The spelling of 1312231221305 in words is "one trillion, three hundred twelve billion, two hundred thirty-one million, two hundred twenty-one thousand, three hundred five".