12557521 has 8 divisors (see below), whose sum is σ = 13077288. Its totient is φ = 12048000.

The previous prime is 12557491. The next prime is 12557549. The reversal of 12557521 is 12575521.

It can be written as a sum of positive squares in 4 ways, for example, as 25921 + 12531600 = 161^2 + 3540^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12557521 - 2¹⁹ = 12033233 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12557521.

It is not an unprimeable number, because it can be changed into a prime (12557561) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10 + ... + 5011.

It is an arithmetic number, because the mean of its divisors is an integer number (1634661).

Almost surely, 2^12557521 is an apocalyptic number.

It is an amenable number.

12557521 is a deficient number, since it is larger than the sum of its proper divisors (519767).

12557521 is an equidigital number, since it uses as much as digits as its factorization.

12557521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5123.

The product of its digits is 3500, while the sum is 28.

The square root of 12557521 is about 3543.6592669161. The cubic root of 12557521 is about 232.4348821375.

The spelling of 12557521 in words is "twelve million, five hundred fifty-seven thousand, five hundred twenty-one".