6627991 has 2 divisors, whose sum is σ = 6627992. Its totient is φ = 6627990.

The previous prime is 6627989. The next prime is 6628007. The reversal of 6627991 is 1997266.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6627991 - 2¹ = 6627989 is a prime.

Together with 6627989, it forms a pair of twin primes.

It is a Chen prime.

6627991 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6627911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3313995 + 3313996.

It is an arithmetic number, because the mean of its divisors is an integer number (3313996).

Almost surely, 2^6627991 is an apocalyptic number.

6627991 is a deficient number, since it is larger than the sum of its proper divisors (1).

6627991 is an equidigital number, since it uses as much as digits as its factorization.

6627991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40824, while the sum is 40.

The square root of 6627991 is about 2574.4884928855. The cubic root of 6627991 is about 187.8425477371.

The spelling of 6627991 in words is "six million, six hundred twenty-seven thousand, nine hundred ninety-one".