666506566 has 8 divisors (see below), whose sum is σ = 1090647144. Its totient is φ = 302957520.

The previous prime is 666506543. The next prime is 666506569. The reversal of 666506566 is 665605666.

666506566 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a super-2 number, since 2×666506566² = 888462005042224712, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666506569) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15147855 + ... + 15147898.

It is an arithmetic number, because the mean of its divisors is an integer number (136330893).

Almost surely, 2^666506566 is an apocalyptic number.

666506566 is a deficient number, since it is larger than the sum of its proper divisors (424140578).

666506566 is a wasteful number, since it uses less digits than its factorization.

666506566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30295766.

The product of its (nonzero) digits is 1166400, while the sum is 46.

The square root of 666506566 is about 25816.7884524780. The cubic root of 666506566 is about 873.5105287302.

The spelling of 666506566 in words is "six hundred sixty-six million, five hundred six thousand, five hundred sixty-six".