1321159538761 has 2 divisors, whose sum is σ = 1321159538762. Its totient is φ = 1321159538760.

The previous prime is 1321159538749. The next prime is 1321159538819. The reversal of 1321159538761 is 1678359511231.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1007132673600 + 314026865161 = 1003560^2 + 560381^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321159538761 - 2³⁵ = 1286799800393 is a prime.

It is a super-2 number, since 2×1321159538761² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1321159538699 and 1321159538708.

It is not a weakly prime, because it can be changed into another prime (1321159538731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660579769380 + 660579769381.

It is an arithmetic number, because the mean of its divisors is an integer number (660579769381).

Almost surely, 2^{1321159538761} is an apocalyptic number.

It is an amenable number.

1321159538761 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321159538761 is an equidigital number, since it uses as much as digits as its factorization.

1321159538761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1360800, while the sum is 52.

The spelling of 1321159538761 in words is "one trillion, three hundred twenty-one billion, one hundred fifty-nine million, five hundred thirty-eight thousand, seven hundred sixty-one".