6678445621 has 2 divisors, whose sum is σ = 6678445622. Its totient is φ = 6678445620.

The previous prime is 6678445607. The next prime is 6678445633. The reversal of 6678445621 is 1265448766.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6148755396 + 529690225 = 78414^2 + 23015^2 .

It is a cyclic number.

It is not a de Polignac number, because 6678445621 - 2¹¹ = 6678443573 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6678440621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3339222810 + 3339222811.

It is an arithmetic number, because the mean of its divisors is an integer number (3339222811).

Almost surely, 2^6678445621 is an apocalyptic number.

It is an amenable number.

6678445621 is a deficient number, since it is larger than the sum of its proper divisors (1).

6678445621 is an equidigital number, since it uses as much as digits as its factorization.

6678445621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1935360, while the sum is 49.

The square root of 6678445621 is about 81721.7573293673. The cubic root of 6678445621 is about 1883.1798476287.

The spelling of 6678445621 in words is "six billion, six hundred seventy-eight million, four hundred forty-five thousand, six hundred twenty-one".