11545791821 has 2 divisors, whose sum is σ = 11545791822. Its totient is φ = 11545791820.

The previous prime is 11545791809. The next prime is 11545791853. The reversal of 11545791821 is 12819754511.

11545791821 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 can be written as a sum of positive squares in only one way, i.e., 10997716900 + 548074921 = 104870^2 + 23411^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11545791821 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11545791221) 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, 5772895910 + 5772895911.

It is an arithmetic number, because the mean of its divisors is an integer number (5772895911).

Almost surely, 2^11545791821 is an apocalyptic number.

It is an amenable number.

11545791821 is a deficient number, since it is larger than the sum of its proper divisors (1).

11545791821 is an equidigital number, since it uses as much as digits as its factorization.

11545791821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 100800, while the sum is 44.

It can be divided in two parts, 1154 and 5791821, that added together give a palindrome (5792975).

The spelling of 11545791821 in words is "eleven billion, five hundred forty-five million, seven hundred ninety-one thousand, eight hundred twenty-one".