663343681 has 16 divisors (see below), whose sum is σ = 890644608. Its totient is φ = 477129600.

The previous prime is 663343669. The next prime is 663343687. The reversal of 663343681 is 186343366.

It is a cyclic number.

It is not a de Polignac number, because 663343681 - 2⁵ = 663343649 is a prime.

It is a super-2 number, since 2×663343681² = 880049678245259522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (663343687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 330340 + ... + 332341.

It is an arithmetic number, because the mean of its divisors is an integer number (55665288).

Almost surely, 2^663343681 is an apocalyptic number.

It is an amenable number.

663343681 is a deficient number, since it is larger than the sum of its proper divisors (227300927).

663343681 is a wasteful number, since it uses less digits than its factorization.

663343681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 662712.

The product of its digits is 186624, while the sum is 40.

The square root of 663343681 is about 25755.4592465365. The cubic root of 663343681 is about 872.1265987846.

The spelling of 663343681 in words is "six hundred sixty-three million, three hundred forty-three thousand, six hundred eighty-one".