8421860309 has 2 divisors, whose sum is σ = 8421860310. Its totient is φ = 8421860308.

The previous prime is 8421860287. The next prime is 8421860311. The reversal of 8421860309 is 9030681248.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7796360209 + 625500100 = 88297^2 + 25010^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8421860309 is a prime.

Together with 8421860311, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8421850309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4210930154 + 4210930155.

It is an arithmetic number, because the mean of its divisors is an integer number (4210930155).

Almost surely, 2^8421860309 is an apocalyptic number.

It is an amenable number.

8421860309 is a deficient number, since it is larger than the sum of its proper divisors (1).

8421860309 is an equidigital number, since it uses as much as digits as its factorization.

8421860309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 82944, while the sum is 41.

The square root of 8421860309 is about 91770.6941730311. The cubic root of 8421860309 is about 2034.5545780819.

The spelling of 8421860309 in words is "eight billion, four hundred twenty-one million, eight hundred sixty thousand, three hundred nine".