6667891 has 2 divisors, whose sum is σ = 6667892. Its totient is φ = 6667890.

The previous prime is 6667889. The next prime is 6667897. The reversal of 6667891 is 1987666.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6667891 - 2¹ = 6667889 is a prime.

Together with 6667889, it forms a pair of twin primes.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (6667897) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3333945 + 3333946.

It is an arithmetic number, because the mean of its divisors is an integer number (3333946).

Almost surely, 2^6667891 is an apocalyptic number.

6667891 is a deficient number, since it is larger than the sum of its proper divisors (1).

6667891 is an equidigital number, since it uses as much as digits as its factorization.

6667891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108864, while the sum is 43.

The square root of 6667891 is about 2582.2259777177. The cubic root of 6667891 is about 188.2187264888.

The spelling of 6667891 in words is "six million, six hundred sixty-seven thousand, eight hundred ninety-one".