12421521 has 24 divisors (see below), whose sum is σ = 20801664. Its totient is φ = 6995520.

The previous prime is 12421517. The next prime is 12421537. The reversal of 12421521 is 12512421.

12421521 is a `hidden beast` number, since 124 + 21 + 521 = 666.

12421521 is digitally balanced in base 2 and base 8, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 12421521 - 2² = 12421517 is a prime.

12421521 is strictly pandigital in base 8.

It is a junction number, because it is equal to n+sod(n) for n = 12421494 and 12421503.

It is not an unprimeable number, because it can be changed into a prime (12421501) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3085 + ... + 5861.

It is an arithmetic number, because the mean of its divisors is an integer number (866736).

Almost surely, 2^12421521 is an apocalyptic number.

It is an amenable number.

12421521 is a deficient number, since it is larger than the sum of its proper divisors (8380143).

12421521 is a wasteful number, since it uses less digits than its factorization.

12421521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2861 (or 2858 counting only the distinct ones).

The product of its digits is 160, while the sum is 18.

The square root of 12421521 is about 3524.4178242654. The cubic root of 12421521 is about 231.5927320153.

Adding to 12421521 its reverse (12512421), we get a palindrome (24933942).

The spelling of 12421521 in words is "twelve million, four hundred twenty-one thousand, five hundred twenty-one".