663455993 has 2 divisors, whose sum is σ = 663455994. Its totient is φ = 663455992.

The previous prime is 663455959. The next prime is 663456029. The reversal of 663455993 is 399554366.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 489427129 + 174028864 = 22123^2 + 13192^2 .

It is a cyclic number.

It is not a de Polignac number, because 663455993 - 2¹⁸ = 663193849 is a prime.

It is not a weakly prime, because it can be changed into another prime (663455393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 331727996 + 331727997.

It is an arithmetic number, because the mean of its divisors is an integer number (331727997).

Almost surely, 2^663455993 is an apocalyptic number.

It is an amenable number.

663455993 is a deficient number, since it is larger than the sum of its proper divisors (1).

663455993 is an equidigital number, since it uses as much as digits as its factorization.

663455993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2624400, while the sum is 50.

The square root of 663455993 is about 25757.6395075325. The cubic root of 663455993 is about 872.1758164867.

The spelling of 663455993 in words is "six hundred sixty-three million, four hundred fifty-five thousand, nine hundred ninety-three".