13855521 has 4 divisors (see below), whose sum is σ = 18474032. Its totient is φ = 9237012.

The previous prime is 13855519. The next prime is 13855549. The reversal of 13855521 is 12555831.

13855521 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

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: 12555831 = 3 ⋅4185277.

It is not a de Polignac number, because 13855521 - 2¹ = 13855519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13855021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2309251 + ... + 2309256.

It is an arithmetic number, because the mean of its divisors is an integer number (4618508).

Almost surely, 2^13855521 is an apocalyptic number.

It is an amenable number.

13855521 is a deficient number, since it is larger than the sum of its proper divisors (4618511).

13855521 is an equidigital number, since it uses as much as digits as its factorization.

13855521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4618510.

The product of its digits is 6000, while the sum is 30.

The square root of 13855521 is about 3722.3004983478. The cubic root of 13855521 is about 240.1822747258.

The spelling of 13855521 in words is "thirteen million, eight hundred fifty-five thousand, five hundred twenty-one".