13521221532521 has 2 divisors, whose sum is σ = 13521221532522. Its totient is φ = 13521221532520.

The previous prime is 13521221532491. The next prime is 13521221532529. The reversal of 13521221532521 is 12523512212531.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12739624086121 + 781597446400 = 3569261^2 + 884080^2 .

It is a cyclic number.

It is not a de Polignac number, because 13521221532521 - 2⁶ = 13521221532457 is a prime.

It is not a weakly prime, because it can be changed into another prime (13521221532529) 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, 6760610766260 + 6760610766261.

It is an arithmetic number, because the mean of its divisors is an integer number (6760610766261).

Almost surely, 2^{13521221532521} is an apocalyptic number.

It is an amenable number.

13521221532521 is a deficient number, since it is larger than the sum of its proper divisors (1).

13521221532521 is an equidigital number, since it uses as much as digits as its factorization.

13521221532521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36000, while the sum is 35.

The spelling of 13521221532521 in words is "thirteen trillion, five hundred twenty-one billion, two hundred twenty-one million, five hundred thirty-two thousand, five hundred twenty-one".