11636721091 has 2 divisors, whose sum is σ = 11636721092. Its totient is φ = 11636721090.

The previous prime is 11636721053. The next prime is 11636721157. The reversal of 11636721091 is 19012763611.

It is a happy number.

11636721091 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 11636721091 - 2³³ = 3046786499 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 11636721091.

It is not a weakly prime, because it can be changed into another prime (11636721491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5818360545 + 5818360546.

It is an arithmetic number, because the mean of its divisors is an integer number (5818360546).

Almost surely, 2^11636721091 is an apocalyptic number.

11636721091 is a deficient number, since it is larger than the sum of its proper divisors (1).

11636721091 is an equidigital number, since it uses as much as digits as its factorization.

11636721091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13608, while the sum is 37.

The spelling of 11636721091 in words is "eleven billion, six hundred thirty-six million, seven hundred twenty-one thousand, ninety-one".