12521305 has 4 divisors (see below), whose sum is σ = 15025572. Its totient is φ = 10017040.

The previous prime is 12521293. The next prime is 12521309. The reversal of 12521305 is 50312521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50312521 = 7 ⋅7187503.

It can be written as a sum of positive squares in 2 ways, for example, as 7733961 + 4787344 = 2781^2 + 2188^2 .

It is not a de Polignac number, because 12521305 - 2⁹ = 12520793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12521309) 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, 1252126 + ... + 1252135.

It is an arithmetic number, because the mean of its divisors is an integer number (3756393).

Almost surely, 2^12521305 is an apocalyptic number.

It is an amenable number.

12521305 is a deficient number, since it is larger than the sum of its proper divisors (2504267).

12521305 is an equidigital number, since it uses as much as digits as its factorization.

12521305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2504266.

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 12521305 is about 3538.5456051887. The cubic root of 12521305 is about 232.2112189087.

Adding to 12521305 its reverse (50312521), we get a palindrome (62833826).

The spelling of 12521305 in words is "twelve million, five hundred twenty-one thousand, three hundred five".