1312111211321 has 4 divisors (see below), whose sum is σ = 1312529483892. Its totient is φ = 1311692938752.

The previous prime is 1312111211267. The next prime is 1312111211353. The reversal of 1312111211321 is 1231121112131.

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 1287689335696 + 24421875625 = 1134764^2 + 156275^2 .

It is a cyclic number.

It is not a de Polignac number, because 1312111211321 - 2¹⁰ = 1312111210297 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1312111211293 and 1312111211302.

It is not an unprimeable number, because it can be changed into a prime (1312111211381) 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, 209131580 + ... + 209137853.

It is an arithmetic number, because the mean of its divisors is an integer number (328132370973).

Almost surely, 2^{1312111211321} is an apocalyptic number.

It is an amenable number.

1312111211321 is a deficient number, since it is larger than the sum of its proper divisors (418272571).

1312111211321 is an equidigital number, since it uses as much as digits as its factorization.

1312111211321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 418272570.

The product of its digits is 72, while the sum is 20.

Adding to 1312111211321 its reverse (1231121112131), we get a palindrome (2543232323452).

The spelling of 1312111211321 in words is "one trillion, three hundred twelve billion, one hundred eleven million, two hundred eleven thousand, three hundred twenty-one".