6666270421 has 2 divisors, whose sum is σ = 6666270422. Its totient is φ = 6666270420.

The previous prime is 6666270419. The next prime is 6666270431. The reversal of 6666270421 is 1240726666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3960814225 + 2705456196 = 62935^2 + 52014^2 .

It is a cyclic number.

It is not a de Polignac number, because 6666270421 - 2¹ = 6666270419 is a prime.

It is a super-2 number, since 2×6666270421² = 88878322651799034482, which contains 22 as substring.

Together with 6666270419, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6666270431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3333135210 + 3333135211.

It is an arithmetic number, because the mean of its divisors is an integer number (3333135211).

Almost surely, 2^6666270421 is an apocalyptic number.

It is an amenable number.

6666270421 is a deficient number, since it is larger than the sum of its proper divisors (1).

6666270421 is an equidigital number, since it uses as much as digits as its factorization.

6666270421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 145152, while the sum is 40.

The square root of 6666270421 is about 81647.2315574754. The cubic root of 6666270421 is about 1882.0347688784.

The spelling of 6666270421 in words is "six billion, six hundred sixty-six million, two hundred seventy thousand, four hundred twenty-one".