6849991 has 2 divisors, whose sum is σ = 6849992. Its totient is φ = 6849990.

The previous prime is 6849971. The next prime is 6850007. The reversal of 6849991 is 1999486.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6849991 - 2¹⁷ = 6718919 is a prime.

6849991 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6849971) 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, 3424995 + 3424996.

It is an arithmetic number, because the mean of its divisors is an integer number (3424996).

Almost surely, 2^6849991 is an apocalyptic number.

6849991 is a deficient number, since it is larger than the sum of its proper divisors (1).

6849991 is an equidigital number, since it uses as much as digits as its factorization.

6849991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 139968, while the sum is 46.

The square root of 6849991 is about 2617.2487462983. The cubic root of 6849991 is about 189.9167779576.

The spelling of 6849991 in words is "six million, eight hundred forty-nine thousand, nine hundred ninety-one".