6631591 has 2 divisors, whose sum is σ = 6631592. Its totient is φ = 6631590.

The previous prime is 6631579. The next prime is 6631607. The reversal of 6631591 is 1951366.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6631591 - 2¹⁷ = 6500519 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6631501) 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, 3315795 + 3315796.

It is an arithmetic number, because the mean of its divisors is an integer number (3315796).

Almost surely, 2^6631591 is an apocalyptic number.

6631591 is a deficient number, since it is larger than the sum of its proper divisors (1).

6631591 is an equidigital number, since it uses as much as digits as its factorization.

6631591 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4860, while the sum is 31.

The square root of 6631591 is about 2575.1875659843. The cubic root of 6631591 is about 187.8765505381.

The spelling of 6631591 in words is "six million, six hundred thirty-one thousand, five hundred ninety-one".