8421641 has 2 divisors, whose sum is σ = 8421642. Its totient is φ = 8421640.

The previous prime is 8421619. The next prime is 8421653. The reversal of 8421641 is 1461248.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5953600 + 2468041 = 2440^2 + 1571^2 .

It is a cyclic number.

It is not a de Polignac number, because 8421641 - 2⁶ = 8421577 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 8421641.

It is not a weakly prime, because it can be changed into another prime (8421041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4210820 + 4210821.

It is an arithmetic number, because the mean of its divisors is an integer number (4210821).

Almost surely, 2^8421641 is an apocalyptic number.

It is an amenable number.

8421641 is a deficient number, since it is larger than the sum of its proper divisors (1).

8421641 is an equidigital number, since it uses as much as digits as its factorization.

8421641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1536, while the sum is 26.

The square root of 8421641 is about 2902.0063749069. The cubic root of 8421641 is about 203.4536917692.

Adding to 8421641 its reverse (1461248), we get a palindrome (9882889).

The spelling of 8421641 in words is "eight million, four hundred twenty-one thousand, six hundred forty-one".