1331169778691 has 2 divisors, whose sum is σ = 1331169778692. Its totient is φ = 1331169778690.

The previous prime is 1331169778663. The next prime is 1331169778711. The reversal of 1331169778691 is 1968779611331.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1331169778691 - 2¹⁰ = 1331169777667 is a prime.

It is not a weakly prime, because it can be changed into another prime (1331169778651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 665584889345 + 665584889346.

It is an arithmetic number, because the mean of its divisors is an integer number (665584889346).

Almost surely, 2^{1331169778691} is an apocalyptic number.

1331169778691 is a deficient number, since it is larger than the sum of its proper divisors (1).

1331169778691 is an equidigital number, since it uses as much as digits as its factorization.

1331169778691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10287648, while the sum is 62.

The spelling of 1331169778691 in words is "one trillion, three hundred thirty-one billion, one hundred sixty-nine million, seven hundred seventy-eight thousand, six hundred ninety-one".