3291991 has 2 divisors, whose sum is σ = 3291992. Its totient is φ = 3291990.

The previous prime is 3291979. The next prime is 3292019. The reversal of 3291991 is 1991923.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 3291991 - 2¹⁷ = 3160919 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3291901) 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, 1645995 + 1645996.

It is an arithmetic number, because the mean of its divisors is an integer number (1645996).

Almost surely, 2^3291991 is an apocalyptic number.

3291991 is a deficient number, since it is larger than the sum of its proper divisors (1).

3291991 is an equidigital number, since it uses as much as digits as its factorization.

3291991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4374, while the sum is 34.

The square root of 3291991 is about 1814.3844686284. The cubic root of 3291991 is about 148.7600148613.

The spelling of 3291991 in words is "three million, two hundred ninety-one thousand, nine hundred ninety-one".