13631521 has 4 divisors (see below), whose sum is σ = 13651200. Its totient is φ = 13611844.

The previous prime is 13631491. The next prime is 13631539. The reversal of 13631521 is 12513631.

It is a happy number.

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: 12513631 = 13 ⋅962587.

It is a cyclic number.

It is not a de Polignac number, because 13631521 - 2⁵ = 13631489 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13631492 and 13631501.

It is not an unprimeable number, because it can be changed into a prime (13631581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8761 + ... + 10198.

It is an arithmetic number, because the mean of its divisors is an integer number (3412800).

Almost surely, 2^13631521 is an apocalyptic number.

It is an amenable number.

13631521 is a deficient number, since it is larger than the sum of its proper divisors (19679).

13631521 is an equidigital number, since it uses as much as digits as its factorization.

13631521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19678.

The product of its digits is 540, while the sum is 22.

The square root of 13631521 is about 3692.0889750926. The cubic root of 13631521 is about 238.8809068022.

The spelling of 13631521 in words is "thirteen million, six hundred thirty-one thousand, five hundred twenty-one".