63665666 has 8 divisors (see below), whose sum is σ = 95661324. Its totient is φ = 31778560.

The previous prime is 63665647. The next prime is 63665687. The reversal of 63665666 is 66656636.

63665666 is digitally balanced in base 2, 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 63664441 + 1225 = 7979^2 + 35^2 .

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

It is a Curzon 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, 25655 + ... + 28026.

Almost surely, 2^63665666 is an apocalyptic number.

63665666 is a deficient number, since it is larger than the sum of its proper divisors (31995658).

63665666 is a wasteful number, since it uses less digits than its factorization.

63665666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54276.

The product of its digits is 699840, while the sum is 44.

The square root of 63665666 is about 7979.0767636363. The cubic root of 63665666 is about 399.3022544188.

The spelling of 63665666 in words is "sixty-three million, six hundred sixty-five thousand, six hundred sixty-six".