663728666 has 8 divisors (see below), whose sum is σ = 1010452800. Its totient is φ = 326911068.

The previous prime is 663728633. The next prime is 663728711. The reversal of 663728666 is 666827366.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2476466 + ... + 2476733.

It is an arithmetic number, because the mean of its divisors is an integer number (126306600).

Almost surely, 2^663728666 is an apocalyptic number.

663728666 is a deficient number, since it is larger than the sum of its proper divisors (346724134).

663728666 is a wasteful number, since it uses less digits than its factorization.

663728666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4953268.

The product of its digits is 2612736, while the sum is 50.

The square root of 663728666 is about 25762.9320148154. The cubic root of 663728666 is about 872.2952849599.

The spelling of 663728666 in words is "six hundred sixty-three million, seven hundred twenty-eight thousand, six hundred sixty-six".