663606091 has 2 divisors, whose sum is σ = 663606092. Its totient is φ = 663606090.

The previous prime is 663606079. The next prime is 663606109. The reversal of 663606091 is 190606366.

Together with next prime (663606109) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 663606091 - 2⁵ = 663606059 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 663606091.

It is not a weakly prime, because it can be changed into another prime (663606991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 331803045 + 331803046.

It is an arithmetic number, because the mean of its divisors is an integer number (331803046).

Almost surely, 2^663606091 is an apocalyptic number.

663606091 is a deficient number, since it is larger than the sum of its proper divisors (1).

663606091 is an equidigital number, since it uses as much as digits as its factorization.

663606091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 34992, while the sum is 37.

The square root of 663606091 is about 25760.5530026046. The cubic root of 663606091 is about 872.2415842120.

The spelling of 663606091 in words is "six hundred sixty-three million, six hundred six thousand, ninety-one".