1291767265549 has 2 divisors, whose sum is σ = 1291767265550. Its totient is φ = 1291767265548.

The previous prime is 1291767265541. The next prime is 1291767265603. The reversal of 1291767265549 is 9455627671921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1269295156900 + 22472108649 = 1126630^2 + 149907^2 .

It is a cyclic number.

It is not a de Polignac number, because 1291767265549 - 2³ = 1291767265541 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1291767265541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 645883632774 + 645883632775.

It is an arithmetic number, because the mean of its divisors is an integer number (645883632775).

Almost surely, 2^{1291767265549} is an apocalyptic number.

It is an amenable number.

1291767265549 is a deficient number, since it is larger than the sum of its proper divisors (1).

1291767265549 is an equidigital number, since it uses as much as digits as its factorization.

1291767265549 is an evil number, because the sum of its binary digits is even.

The product of its digits is 57153600, while the sum is 64.

The spelling of 1291767265549 in words is "one trillion, two hundred ninety-one billion, seven hundred sixty-seven million, two hundred sixty-five thousand, five hundred forty-nine".