11681550803521 has 2 divisors, whose sum is σ = 11681550803522. Its totient is φ = 11681550803520.

The previous prime is 11681550803519. The next prime is 11681550803551. The reversal of 11681550803521 is 12530805518611.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10847214707121 + 834336096400 = 3293511^2 + 913420^2 .

It is a cyclic number.

It is not a de Polignac number, because 11681550803521 - 2¹ = 11681550803519 is a prime.

Together with 11681550803519, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (11681550803501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5840775401760 + 5840775401761.

It is an arithmetic number, because the mean of its divisors is an integer number (5840775401761).

Almost surely, 2^{11681550803521} is an apocalyptic number.

It is an amenable number.

11681550803521 is a deficient number, since it is larger than the sum of its proper divisors (1).

11681550803521 is an equidigital number, since it uses as much as digits as its factorization.

11681550803521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288000, while the sum is 46.

The spelling of 11681550803521 in words is "eleven trillion, six hundred eighty-one billion, five hundred fifty million, eight hundred three thousand, five hundred twenty-one".