11515136610221 has 2 divisors, whose sum is σ = 11515136610222. Its totient is φ = 11515136610220.

The previous prime is 11515136610193. The next prime is 11515136610239. The reversal of 11515136610221 is 12201663151511.

11515136610221 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., 11391563269321 + 123573340900 = 3375139^2 + 351530^2 .

It is a cyclic number.

It is not a de Polignac number, because 11515136610221 - 2¹⁴ = 11515136593837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11515136610281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5757568305110 + 5757568305111.

It is an arithmetic number, because the mean of its divisors is an integer number (5757568305111).

Almost surely, 2^{11515136610221} is an apocalyptic number.

It is an amenable number.

11515136610221 is a deficient number, since it is larger than the sum of its proper divisors (1).

11515136610221 is an equidigital number, since it uses as much as digits as its factorization.

11515136610221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10800, while the sum is 35.

Adding to 11515136610221 its reverse (12201663151511), we get a palindrome (23716799761732).

The spelling of 11515136610221 in words is "eleven trillion, five hundred fifteen billion, one hundred thirty-six million, six hundred ten thousand, two hundred twenty-one".