12721091 has 2 divisors, whose sum is σ = 12721092. Its totient is φ = 12721090.

The previous prime is 12721087. The next prime is 12721097. The reversal of 12721091 is 19012721.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 12721091 - 2² = 12721087 is a prime.

It is not a weakly prime, because it can be changed into another prime (12721097) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6360545 + 6360546.

It is an arithmetic number, because the mean of its divisors is an integer number (6360546).

Almost surely, 2^12721091 is an apocalyptic number.

12721091 is a deficient number, since it is larger than the sum of its proper divisors (1).

12721091 is an equidigital number, since it uses as much as digits as its factorization.

12721091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 252, while the sum is 23.

The square root of 12721091 is about 3566.6638473509. The cubic root of 12721091 is about 233.4397376381.

The spelling of 12721091 in words is "twelve million, seven hundred twenty-one thousand, ninety-one".