12878521 has 2 divisors, whose sum is σ = 12878522. Its totient is φ = 12878520.

The previous prime is 12878519. The next prime is 12878531. The reversal of 12878521 is 12587821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12531600 + 346921 = 3540^2 + 589^2 .

It is an emirp because it is prime and its reverse (12587821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12878521 - 2¹ = 12878519 is a prime.

Together with 12878519, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (12878531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6439260 + 6439261.

It is an arithmetic number, because the mean of its divisors is an integer number (6439261).

Almost surely, 2^12878521 is an apocalyptic number.

It is an amenable number.

12878521 is a deficient number, since it is larger than the sum of its proper divisors (1).

12878521 is an equidigital number, since it uses as much as digits as its factorization.

12878521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8960, while the sum is 34.

The square root of 12878521 is about 3588.6656294506. The cubic root of 12878521 is about 234.3987709460.

The spelling of 12878521 in words is "twelve million, eight hundred seventy-eight thousand, five hundred twenty-one".