663551999 has 8 divisors (see below), whose sum is σ = 724066560. Its totient is φ = 603069400.

The previous prime is 663551983. The next prime is 663552011. The reversal of 663551999 is 999155366.

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 663551999 - 2⁴ = 663551983 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 663551999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663551699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62522 + ... + 72360.

It is an arithmetic number, because the mean of its divisors is an integer number (90508320).

Almost surely, 2^663551999 is an apocalyptic number.

663551999 is a deficient number, since it is larger than the sum of its proper divisors (60514561).

663551999 is a wasteful number, since it uses less digits than its factorization.

663551999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15981.

The product of its digits is 1968300, while the sum is 53.

The square root of 663551999 is about 25759.5030813873. The cubic root of 663551999 is about 872.2178841213.

The spelling of 663551999 in words is "six hundred sixty-three million, five hundred fifty-one thousand, nine hundred ninety-nine".