13521491281 has 4 divisors (see below), whose sum is σ = 13776613812. Its totient is φ = 13266368752.

The previous prime is 13521491261. The next prime is 13521491287. The reversal of 13521491281 is 18219412531.

13521491281 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11266761025 + 2254730256 = 106145^2 + 47484^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13521491281 is a prime.

It is a super-2 number, since 2×13521491281² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 13521491281.

It is not an unprimeable number, because it can be changed into a prime (13521491287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 127561186 + ... + 127561291.

It is an arithmetic number, because the mean of its divisors is an integer number (3444153453).

Almost surely, 2^13521491281 is an apocalyptic number.

It is an amenable number.

13521491281 is a deficient number, since it is larger than the sum of its proper divisors (255122531).

13521491281 is an equidigital number, since it uses as much as digits as its factorization.

13521491281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255122530.

The product of its digits is 17280, while the sum is 37.

The spelling of 13521491281 in words is "thirteen billion, five hundred twenty-one million, four hundred ninety-one thousand, two hundred eighty-one".