1291389068549 has 8 divisors (see below), whose sum is σ = 1309655423832. Its totient is φ = 1273138283520.

The previous prime is 1291389068531. The next prime is 1291389068647. The reversal of 1291389068549 is 9458609831921.

It can be written as a sum of positive squares in 4 ways, for example, as 720110079649 + 571278988900 = 848593^2 + 755830^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1291389068549 - 2²⁰ = 1291388019973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291389068149) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3725462 + ... + 4057319.

It is an arithmetic number, because the mean of its divisors is an integer number (163706927979).

Almost surely, 2^{1291389068549} is an apocalyptic number.

It is an amenable number.

1291389068549 is a deficient number, since it is larger than the sum of its proper divisors (18266355283).

1291389068549 is an equidigital number, since it uses as much as digits as its factorization.

1291389068549 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7785127.

The product of its (nonzero) digits is 33592320, while the sum is 65.

The spelling of 1291389068549 in words is "one trillion, two hundred ninety-one billion, three hundred eighty-nine million, sixty-eight thousand, five hundred forty-nine".