663645440 has 36 divisors (see below), whose sum is σ = 1589641284. Its totient is φ = 265457664.

The previous prime is 663645419. The next prime is 663645457. The reversal of 663645440 is 44546366.

It is a happy number.

663645440 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 331531264 + 332114176 = 18208^2 + 18224^2 .

It is a junction number, because it is equal to n+sod(n) for n = 663645394 and 663645403.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 257957 + ... + 260516.

Almost surely, 2^663645440 is an apocalyptic number.

It is an amenable number.

663645440 is an abundant number, since it is smaller than the sum of its proper divisors (925995844).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

663645440 is an equidigital number, since it uses as much as digits as its factorization.

663645440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 518494 (or 518480 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 38.

The square root of 663645440 is about 25761.3167365335. The cubic root of 663645440 is about 872.2588239351.

The spelling of 663645440 in words is "six hundred sixty-three million, six hundred forty-five thousand, four hundred forty".