12491321 has 2 divisors, whose sum is σ = 12491322. Its totient is φ = 12491320.

The previous prime is 12491299. The next prime is 12491329. The reversal of 12491321 is 12319421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11833600 + 657721 = 3440^2 + 811^2 .

It is a cyclic number.

It is not a de Polignac number, because 12491321 - 2¹⁴ = 12474937 is a prime.

It is not a weakly prime, because it can be changed into another prime (12491329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6245660 + 6245661.

It is an arithmetic number, because the mean of its divisors is an integer number (6245661).

Almost surely, 2^12491321 is an apocalyptic number.

It is an amenable number.

12491321 is a deficient number, since it is larger than the sum of its proper divisors (1).

12491321 is an equidigital number, since it uses as much as digits as its factorization.

12491321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432, while the sum is 23.

The square root of 12491321 is about 3534.3062968566. The cubic root of 12491321 is about 232.0257167786.

The spelling of 12491321 in words is "twelve million, four hundred ninety-one thousand, three hundred twenty-one".