8241721 has 2 divisors, whose sum is σ = 8241722. Its totient is φ = 8241720.

The previous prime is 8241703. The next prime is 8241749. The reversal of 8241721 is 1271428.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7502121 + 739600 = 2739^2 + 860^2 .

It is a cyclic number.

It is not a de Polignac number, because 8241721 - 2⁷ = 8241593 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8241781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4120860 + 4120861.

It is an arithmetic number, because the mean of its divisors is an integer number (4120861).

Almost surely, 2^8241721 is an apocalyptic number.

It is an amenable number.

8241721 is a deficient number, since it is larger than the sum of its proper divisors (1).

8241721 is an equidigital number, since it uses as much as digits as its factorization.

8241721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 896, while the sum is 25.

The square root of 8241721 is about 2870.8397726101. The cubic root of 8241721 is about 201.9943876492.

The spelling of 8241721 in words is "eight million, two hundred forty-one thousand, seven hundred twenty-one".