12521605 has 16 divisors (see below), whose sum is σ = 16302384. Its totient is φ = 9195520.

The previous prime is 12521603. The next prime is 12521623. The reversal of 12521605 is 50612521.

It can be written as a sum of positive squares in 8 ways, for example, as 1083681 + 11437924 = 1041^2 + 3382^2 .

It is not a de Polignac number, because 12521605 - 2¹ = 12521603 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12521603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1689 + ... + 5281.

It is an arithmetic number, because the mean of its divisors is an integer number (1018899).

Almost surely, 2^12521605 is an apocalyptic number.

It is an amenable number.

12521605 is a deficient number, since it is larger than the sum of its proper divisors (3780779).

12521605 is a wasteful number, since it uses less digits than its factorization.

12521605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3656.

The product of its (nonzero) digits is 600, while the sum is 22.

The square root of 12521605 is about 3538.5879952320. The cubic root of 12521605 is about 232.2130734228.

The spelling of 12521605 in words is "twelve million, five hundred twenty-one thousand, six hundred five".