12055521 has 4 divisors (see below), whose sum is σ = 16074032. Its totient is φ = 8037012.

The previous prime is 12055513. The next prime is 12055531. The reversal of 12055521 is 12555021.

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: 12555021 = 3 ⋅4185007.

It is not a de Polignac number, because 12055521 - 2³ = 12055513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12055531) 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, 2009251 + ... + 2009256.

It is an arithmetic number, because the mean of its divisors is an integer number (4018508).

Almost surely, 2^12055521 is an apocalyptic number.

It is an amenable number.

12055521 is a deficient number, since it is larger than the sum of its proper divisors (4018511).

12055521 is an equidigital number, since it uses as much as digits as its factorization.

12055521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4018510.

The product of its (nonzero) digits is 500, while the sum is 21.

The square root of 12055521 is about 3472.1061331705. The cubic root of 12055521 is about 229.2953924656.

Subtracting from 12055521 its product of nonzero digits (500), we obtain a palindrome (12055021).

Subtracting 12055521 from its reverse (12555021), we obtain a triangular number (499500 = T₉₉₉).

The spelling of 12055521 in words is "twelve million, fifty-five thousand, five hundred twenty-one".