11521421321 has 2 divisors, whose sum is σ = 11521421322. Its totient is φ = 11521421320.

The previous prime is 11521421279. The next prime is 11521421347. The reversal of 11521421321 is 12312412511.

11521421321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10188076096 + 1333345225 = 100936^2 + 36515^2 .

It is a cyclic number.

It is not a de Polignac number, because 11521421321 - 2¹⁰ = 11521420297 is a prime.

It is not a weakly prime, because it can be changed into another prime (11521471321) 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, 5760710660 + 5760710661.

It is an arithmetic number, because the mean of its divisors is an integer number (5760710661).

Almost surely, 2^11521421321 is an apocalyptic number.

It is an amenable number.

11521421321 is a deficient number, since it is larger than the sum of its proper divisors (1).

11521421321 is an equidigital number, since it uses as much as digits as its factorization.

11521421321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 480, while the sum is 23.

Adding to 11521421321 its reverse (12312412511), we get a palindrome (23833833832).

The spelling of 11521421321 in words is "eleven billion, five hundred twenty-one million, four hundred twenty-one thousand, three hundred twenty-one".