666525666 has 8 divisors (see below), whose sum is σ = 1333051344. Its totient is φ = 222175220.

The previous prime is 666525649. The next prime is 666525679.

666525666 is nontrivially palindromic in base 10.

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

666525666 is an admirable number.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55543800 + ... + 55543811.

It is an arithmetic number, because the mean of its divisors is an integer number (166631418).

Almost surely, 2^666525666 is an apocalyptic number.

666525666 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

666525666 is a wasteful number, since it uses less digits than its factorization.

666525666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111087616.

The product of its digits is 2332800, while the sum is 48.

The square root of 666525666 is about 25817.1583641577. The cubic root of 666525666 is about 873.5188726799.

The spelling of 666525666 in words is "six hundred sixty-six million, five hundred twenty-five thousand, six hundred sixty-six".