13616521 has 4 divisors (see below), whose sum is σ = 14333200. Its totient is φ = 12899844.

The previous prime is 13616503. The next prime is 13616527. The reversal of 13616521 is 12561631.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12561631 = 59 ⋅212909.

It is a cyclic number.

It is not a de Polignac number, because 13616521 - 2¹⁵ = 13583753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13616527) 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, 358311 + ... + 358348.

It is an arithmetic number, because the mean of its divisors is an integer number (3583300).

Almost surely, 2^13616521 is an apocalyptic number.

It is an amenable number.

13616521 is a deficient number, since it is larger than the sum of its proper divisors (716679).

13616521 is an equidigital number, since it uses as much as digits as its factorization.

13616521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 716678.

The product of its digits is 1080, while the sum is 25.

The square root of 13616521 is about 3690.0570456295. The cubic root of 13616521 is about 238.7932538612.

The spelling of 13616521 in words is "thirteen million, six hundred sixteen thousand, five hundred twenty-one".