6668825021 has 2 divisors, whose sum is σ = 6668825022. Its totient is φ = 6668825020.

The previous prime is 6668825017. The next prime is 6668825027. The reversal of 6668825021 is 1205288666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3754012900 + 2914812121 = 61270^2 + 53989^2 .

It is a cyclic number.

It is not a de Polignac number, because 6668825021 - 2² = 6668825017 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6668825027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3334412510 + 3334412511.

It is an arithmetic number, because the mean of its divisors is an integer number (3334412511).

Almost surely, 2^6668825021 is an apocalyptic number.

It is an amenable number.

6668825021 is a deficient number, since it is larger than the sum of its proper divisors (1).

6668825021 is an equidigital number, since it uses as much as digits as its factorization.

6668825021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 276480, while the sum is 44.

The square root of 6668825021 is about 81662.8741901729. The cubic root of 6668825021 is about 1882.2751447660.

The spelling of 6668825021 in words is "six billion, six hundred sixty-eight million, eight hundred twenty-five thousand, twenty-one".