2191931165377 has 2 divisors, whose sum is σ = 2191931165378. Its totient is φ = 2191931165376.

The previous prime is 2191931165269. The next prime is 2191931165503. The reversal of 2191931165377 is 7735611391912.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1342715467536 + 849215697841 = 1158756^2 + 921529^2 .

It is a cyclic number.

It is not a de Polignac number, because 2191931165377 - 2¹¹ = 2191931163329 is a prime.

It is not a weakly prime, because it can be changed into another prime (2191931163377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1095965582688 + 1095965582689.

It is an arithmetic number, because the mean of its divisors is an integer number (1095965582689).

Almost surely, 2^{2191931165377} is an apocalyptic number.

It is an amenable number.

2191931165377 is a deficient number, since it is larger than the sum of its proper divisors (1).

2191931165377 is an equidigital number, since it uses as much as digits as its factorization.

2191931165377 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2143260, while the sum is 55.

The spelling of 2191931165377 in words is "two trillion, one hundred ninety-one billion, nine hundred thirty-one million, one hundred sixty-five thousand, three hundred seventy-seven".