12531573521 has 2 divisors, whose sum is σ = 12531573522. Its totient is φ = 12531573520.

The previous prime is 12531573451. The next prime is 12531573539. The reversal of 12531573521 is 12537513521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10904580625 + 1626992896 = 104425^2 + 40336^2 .

It is a cyclic number.

It is not a de Polignac number, because 12531573521 - 2¹⁰ = 12531572497 is a prime.

It is not a weakly prime, because it can be changed into another prime (12531573581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6265786760 + 6265786761.

It is an arithmetic number, because the mean of its divisors is an integer number (6265786761).

Almost surely, 2^12531573521 is an apocalyptic number.

It is an amenable number.

12531573521 is a deficient number, since it is larger than the sum of its proper divisors (1).

12531573521 is an equidigital number, since it uses as much as digits as its factorization.

12531573521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31500, while the sum is 35.

The spelling of 12531573521 in words is "twelve billion, five hundred thirty-one million, five hundred seventy-three thousand, five hundred twenty-one".