13531520521 has 2 divisors, whose sum is σ = 13531520522. Its totient is φ = 13531520520.

The previous prime is 13531520507. The next prime is 13531520537. The reversal of 13531520521 is 12502513531.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12954992400 + 576528121 = 113820^2 + 24011^2 .

It is a cyclic number.

It is not a de Polignac number, because 13531520521 - 2²⁵ = 13497966089 is a prime.

It is a super-2 number, since 2×13531520521² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 13531520521.

It is not a weakly prime, because it can be changed into another prime (13531520221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6765760260 + 6765760261.

It is an arithmetic number, because the mean of its divisors is an integer number (6765760261).

Almost surely, 2^13531520521 is an apocalyptic number.

It is an amenable number.

13531520521 is a deficient number, since it is larger than the sum of its proper divisors (1).

13531520521 is an equidigital number, since it uses as much as digits as its factorization.

13531520521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4500, while the sum is 28.

The spelling of 13531520521 in words is "thirteen billion, five hundred thirty-one million, five hundred twenty thousand, five hundred twenty-one".