12115521 has 48 divisors (see below), whose sum is σ = 20848320. Its totient is φ = 6894720.

The previous prime is 12115517. The next prime is 12115531. The reversal of 12115521 is 12551121.

12115521 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 not a de Polignac number, because 12115521 - 2² = 12115517 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 12115494 and 12115503.

It is not an unprimeable number, because it can be changed into a prime (12115501) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 107161 + ... + 107273.

It is an arithmetic number, because the mean of its divisors is an integer number (434340).

Almost surely, 2^12115521 is an apocalyptic number.

12115521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12115521 is a deficient number, since it is larger than the sum of its proper divisors (8732799).

12115521 is a wasteful number, since it uses less digits than its factorization.

12115521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171 (or 146 counting only the distinct ones).

The product of its digits is 100, while the sum is 18.

The square root of 12115521 is about 3480.7356980960. The cubic root of 12115521 is about 229.6751621028.

Subtracting from 12115521 its sum of digits (18), we obtain a triangular number (12115503 = T₄₉₂₂).

Adding to 12115521 its reverse (12551121), we get a palindrome (24666642).

Subtracting 12115521 from its reverse (12551121), we obtain a square (435600 = 660²).

The spelling of 12115521 in words is "twelve million, one hundred fifteen thousand, five hundred twenty-one".