13491521 has 4 divisors (see below), whose sum is σ = 13746132. Its totient is φ = 13236912.

The previous prime is 13491509. The next prime is 13491529. The reversal of 13491521 is 12519431.

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 8473921 + 5017600 = 2911^2 + 2240^2 .

It is a cyclic number.

It is not a de Polignac number, because 13491521 - 2²² = 9297217 is a prime.

It is a super-2 number, since 2×13491521² = 364042277786882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13491529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 127226 + ... + 127331.

It is an arithmetic number, because the mean of its divisors is an integer number (3436533).

Almost surely, 2^13491521 is an apocalyptic number.

It is an amenable number.

13491521 is a deficient number, since it is larger than the sum of its proper divisors (254611).

13491521 is an equidigital number, since it uses as much as digits as its factorization.

13491521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 254610.

The product of its digits is 1080, while the sum is 26.

The square root of 13491521 is about 3673.0805871911. The cubic root of 13491521 is about 238.0602970827.

The spelling of 13491521 in words is "thirteen million, four hundred ninety-one thousand, five hundred twenty-one".