6001991 has 2 divisors, whose sum is σ = 6001992. Its totient is φ = 6001990.

The previous prime is 6001981. The next prime is 6001997. The reversal of 6001991 is 1991006.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6001991 is a prime.

It is a Chen prime.

It is equal to p₄₁₂₉₇₃ and since 6001991 and 412973 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6001991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6001997) 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, 3000995 + 3000996.

It is an arithmetic number, because the mean of its divisors is an integer number (3000996).

Almost surely, 2^6001991 is an apocalyptic number.

6001991 is a deficient number, since it is larger than the sum of its proper divisors (1).

6001991 is an equidigital number, since it uses as much as digits as its factorization.

6001991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 486, while the sum is 26.

The square root of 6001991 is about 2449.8961202467. The cubic root of 6001991 is about 181.7321564332.

Adding to 6001991 its reverse (1991006), we get a palindrome (7992997).

The spelling of 6001991 in words is "six million, one thousand, nine hundred ninety-one".