6991967 has 2 divisors, whose sum is σ = 6991968. Its totient is φ = 6991966.

The previous prime is 6991951. The next prime is 6991969. The reversal of 6991967 is 7691996.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6991967 - 2⁴ = 6991951 is a prime.

Together with 6991969, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6991969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3495983 + 3495984.

It is an arithmetic number, because the mean of its divisors is an integer number (3495984).

Almost surely, 2^6991967 is an apocalyptic number.

6991967 is a deficient number, since it is larger than the sum of its proper divisors (1).

6991967 is an equidigital number, since it uses as much as digits as its factorization.

6991967 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 183708, while the sum is 47.

The square root of 6991967 is about 2644.2327809783. The cubic root of 6991967 is about 191.2199160962.

The spelling of 6991967 in words is "six million, nine hundred ninety-one thousand, nine hundred sixty-seven".