1311000009961 has 2 divisors, whose sum is σ = 1311000009962. Its totient is φ = 1311000009960.

The previous prime is 1311000009881. The next prime is 1311000009997. The reversal of 1311000009961 is 1699000001131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1229923142361 + 81076867600 = 1109019^2 + 284740^2 .

It is a cyclic number.

It is not a de Polignac number, because 1311000009961 - 2¹⁹ = 1310999485673 is a prime.

It is a super-2 number, since 2×1311000009961² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1311000004961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 655500004980 + 655500004981.

It is an arithmetic number, because the mean of its divisors is an integer number (655500004981).

Almost surely, 2^{1311000009961} is an apocalyptic number.

It is an amenable number.

1311000009961 is a deficient number, since it is larger than the sum of its proper divisors (1).

1311000009961 is an equidigital number, since it uses as much as digits as its factorization.

1311000009961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1458, while the sum is 31.

The spelling of 1311000009961 in words is "one trillion, three hundred eleven billion, nine thousand, nine hundred sixty-one".