663567666 has 16 divisors (see below), whose sum is σ = 1396984800. Its totient is φ = 209547648.

The previous prime is 663567661. The next prime is 663567683. The reversal of 663567666 is 666765366.

It is not an unprimeable number, because it can be changed into a prime (663567661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2910271 + ... + 2910498.

It is an arithmetic number, because the mean of its divisors is an integer number (87311550).

Almost surely, 2^663567666 is an apocalyptic number.

663567666 is an abundant number, since it is smaller than the sum of its proper divisors (733417134).

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

663567666 is a wasteful number, since it uses less digits than its factorization.

663567666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5820793.

The product of its digits is 4898880, while the sum is 51.

The square root of 663567666 is about 25759.8071809554. The cubic root of 663567666 is about 872.2247486574.

The spelling of 663567666 in words is "six hundred sixty-three million, five hundred sixty-seven thousand, six hundred sixty-six".