1312023031981 has 2 divisors, whose sum is σ = 1312023031982. Its totient is φ = 1312023031980.

The previous prime is 1312023031961. The next prime is 1312023032017. The reversal of 1312023031981 is 1891303202131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1046803181956 + 265219850025 = 1023134^2 + 514995^2 .

It is a cyclic number.

It is not a de Polignac number, because 1312023031981 - 2¹³ = 1312023023789 is a prime.

It is a super-2 number, since 2×1312023031981² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1312023031961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 656011515990 + 656011515991.

It is an arithmetic number, because the mean of its divisors is an integer number (656011515991).

Almost surely, 2^{1312023031981} is an apocalyptic number.

It is an amenable number.

1312023031981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1312023031981 is an equidigital number, since it uses as much as digits as its factorization.

1312023031981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 34.

The spelling of 1312023031981 in words is "one trillion, three hundred twelve billion, twenty-three million, thirty-one thousand, nine hundred eighty-one".