12406521 has 4 divisors (see below), whose sum is σ = 16542032. Its totient is φ = 8271012.

The previous prime is 12406517. The next prime is 12406529. The reversal of 12406521 is 12560421.

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.

It is not a de Polignac number, because 12406521 - 2² = 12406517 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12406529) 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, 2067751 + ... + 2067756.

It is an arithmetic number, because the mean of its divisors is an integer number (4135508).

Almost surely, 2^12406521 is an apocalyptic number.

It is an amenable number.

12406521 is a deficient number, since it is larger than the sum of its proper divisors (4135511).

12406521 is an equidigital number, since it uses as much as digits as its factorization.

12406521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4135510.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 12406521 is about 3522.2891704118. The cubic root of 12406521 is about 231.4994720929.

Adding to 12406521 its reverse (12560421), we get a palindrome (24966942).

The spelling of 12406521 in words is "twelve million, four hundred six thousand, five hundred twenty-one".