12545821 has 2 divisors, whose sum is σ = 12545822. Its totient is φ = 12545820.

The previous prime is 12545803. The next prime is 12545843. The reversal of 12545821 is 12854521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9703225 + 2842596 = 3115^2 + 1686^2 .

It is an emirp because it is prime and its reverse (12854521) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12545821 - 2⁷ = 12545693 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12545821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12545801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6272910 + 6272911.

It is an arithmetic number, because the mean of its divisors is an integer number (6272911).

Almost surely, 2^12545821 is an apocalyptic number.

It is an amenable number.

12545821 is a deficient number, since it is larger than the sum of its proper divisors (1).

12545821 is an equidigital number, since it uses as much as digits as its factorization.

12545821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3200, while the sum is 28.

The square root of 12545821 is about 3542.0080462924. The cubic root of 12545821 is about 232.3626722071.

It can be divided in two parts, 12545 and 821, that added together give a triangular number (13366 = T₁₆₃).

The spelling of 12545821 in words is "twelve million, five hundred forty-five thousand, eight hundred twenty-one".