663643591 has 8 divisors (see below), whose sum is σ = 716066960. Its totient is φ = 611416512.

The previous prime is 663643577. The next prime is 663643649. The reversal of 663643591 is 195346366.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 663643591 - 2¹¹ = 663641543 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663623591) 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 in 7 ways as a sum of consecutive naturals, for example, 42006 + ... + 55603.

It is an arithmetic number, because the mean of its divisors is an integer number (89508370).

Almost surely, 2^663643591 is an apocalyptic number.

663643591 is a deficient number, since it is larger than the sum of its proper divisors (52423369).

663643591 is a wasteful number, since it uses less digits than its factorization.

663643591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98145.

The product of its digits is 349920, while the sum is 43.

The square root of 663643591 is about 25761.2808493677. The cubic root of 663643591 is about 872.2580138600.

The spelling of 663643591 in words is "six hundred sixty-three million, six hundred forty-three thousand, five hundred ninety-one".