1312311211021 has 2 divisors, whose sum is σ = 1312311211022. Its totient is φ = 1312311211020.

The previous prime is 1312311210943. The next prime is 1312311211067. The reversal of 1312311211021 is 1201121132131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1163677830121 + 148633380900 = 1078739^2 + 385530^2 .

It is a cyclic number.

It is not a de Polignac number, because 1312311211021 - 2¹⁵ = 1312311178253 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1312311211021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1312311211121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 656155605510 + 656155605511.

It is an arithmetic number, because the mean of its divisors is an integer number (656155605511).

Almost surely, 2^{1312311211021} is an apocalyptic number.

It is an amenable number.

1312311211021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1312311211021 is an equidigital number, since it uses as much as digits as its factorization.

1312311211021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 19.

Adding to 1312311211021 its reverse (1201121132131), we get a palindrome (2513432343152).

The spelling of 1312311211021 in words is "one trillion, three hundred twelve billion, three hundred eleven million, two hundred eleven thousand, twenty-one".