11891306731597 has 2 divisors, whose sum is σ = 11891306731598. Its totient is φ = 11891306731596.

The previous prime is 11891306731583. The next prime is 11891306731663. The reversal of 11891306731597 is 79513760319811.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10948283174761 + 943023556836 = 3308819^2 + 971094^2 .

It is an emirp because it is prime and its reverse (79513760319811) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11891306731597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11891306731517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5945653365798 + 5945653365799.

It is an arithmetic number, because the mean of its divisors is an integer number (5945653365799).

Almost surely, 2^{11891306731597} is an apocalyptic number.

It is an amenable number.

11891306731597 is a deficient number, since it is larger than the sum of its proper divisors (1).

11891306731597 is an equidigital number, since it uses as much as digits as its factorization.

11891306731597 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8573040, while the sum is 61.

The spelling of 11891306731597 in words is "eleven trillion, eight hundred ninety-one billion, three hundred six million, seven hundred thirty-one thousand, five hundred ninety-seven".