12507821 has 2 divisors, whose sum is σ = 12507822. Its totient is φ = 12507820.

The previous prime is 12507773. The next prime is 12507827. The reversal of 12507821 is 12870521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10982596 + 1525225 = 3314^2 + 1235^2 .

It is an emirp because it is prime and its reverse (12870521) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12507821 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 (12507827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6253910 + 6253911.

It is an arithmetic number, because the mean of its divisors is an integer number (6253911).

Almost surely, 2^12507821 is an apocalyptic number.

It is an amenable number.

12507821 is a deficient number, since it is larger than the sum of its proper divisors (1).

12507821 is an equidigital number, since it uses as much as digits as its factorization.

12507821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1120, while the sum is 26.

The square root of 12507821 is about 3536.6397894046. The cubic root of 12507821 is about 232.1278340777.

The spelling of 12507821 in words is "twelve million, five hundred seven thousand, eight hundred twenty-one".