12547421 has 2 divisors, whose sum is σ = 12547422. Its totient is φ = 12547420.

The previous prime is 12547417. The next prime is 12547427. The reversal of 12547421 is 12474521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6446521 + 6100900 = 2539^2 + 2470^2 .

It is a cyclic number.

It is not a de Polignac number, because 12547421 - 2² = 12547417 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12547427) 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, 6273710 + 6273711.

It is an arithmetic number, because the mean of its divisors is an integer number (6273711).

Almost surely, 2^12547421 is an apocalyptic number.

It is an amenable number.

12547421 is a deficient number, since it is larger than the sum of its proper divisors (1).

12547421 is an equidigital number, since it uses as much as digits as its factorization.

12547421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2240, while the sum is 26.

The square root of 12547421 is about 3542.2338996740. The cubic root of 12547421 is about 232.3725497186.

Subtracting from 12547421 its reverse (12474521), we obtain a square (72900 = 270²).

The spelling of 12547421 in words is "twelve million, five hundred forty-seven thousand, four hundred twenty-one".