13521212521 has 2 divisors, whose sum is σ = 13521212522. Its totient is φ = 13521212520.

The previous prime is 13521212513. The next prime is 13521212527. The reversal of 13521212521 is 12521212531.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8288281600 + 5232930921 = 91040^2 + 72339^2 .

It is a cyclic number.

It is not a de Polignac number, because 13521212521 - 2³ = 13521212513 is a prime.

It is not a weakly prime, because it can be changed into another prime (13521212527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6760606260 + 6760606261.

It is an arithmetic number, because the mean of its divisors is an integer number (6760606261).

Almost surely, 2^13521212521 is an apocalyptic number.

It is an amenable number.

13521212521 is a deficient number, since it is larger than the sum of its proper divisors (1).

13521212521 is an equidigital number, since it uses as much as digits as its factorization.

13521212521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1200, while the sum is 25.

The spelling of 13521212521 in words is "thirteen billion, five hundred twenty-one million, two hundred twelve thousand, five hundred twenty-one".