11855584909991 has 2 divisors, whose sum is σ = 11855584909992. Its totient is φ = 11855584909990.

The previous prime is 11855584909981. The next prime is 11855584910003. The reversal of 11855584909991 is 19990948555811.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11855584909991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11855584909921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5927792454995 + 5927792454996.

It is an arithmetic number, because the mean of its divisors is an integer number (5927792454996).

Almost surely, 2^{11855584909991} is an apocalyptic number.

11855584909991 is a deficient number, since it is larger than the sum of its proper divisors (1).

11855584909991 is an equidigital number, since it uses as much as digits as its factorization.

11855584909991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 209952000, while the sum is 74.

The spelling of 11855584909991 in words is "eleven trillion, eight hundred fifty-five billion, five hundred eighty-four million, nine hundred nine thousand, nine hundred ninety-one".