663191 has 2 divisors, whose sum is σ = 663192. Its totient is φ = 663190.

The previous prime is 663167. The next prime is 663203. The reversal of 663191 is 191366.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 663191 - 2⁶ = 663127 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 663191.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (663161) 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, 331595 + 331596.

It is an arithmetic number, because the mean of its divisors is an integer number (331596).

2⁶⁶³¹⁹¹ is an apocalyptic number.

663191 is a deficient number, since it is larger than the sum of its proper divisors (1).

663191 is an equidigital number, since it uses as much as digits as its factorization.

663191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 972, while the sum is 26.

The square root of 663191 is about 814.3653971038. The cubic root of 663191 is about 87.2059681548.

The spelling of 663191 in words is "six hundred sixty-three thousand, one hundred ninety-one".