664555764666 has 8 divisors (see below), whose sum is σ = 1329111529344. Its totient is φ = 221518588220.

The previous prime is 664555764619. The next prime is 664555764671. The reversal of 664555764666 is 666467555466.

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

664555764666 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 664555764597 and 664555764606.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55379647050 + ... + 55379647061.

It is an arithmetic number, because the mean of its divisors is an integer number (166138941168).

Almost surely, 2^664555764666 is an apocalyptic number.

664555764666 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.

664555764666 is a wasteful number, since it uses less digits than its factorization.

664555764666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110759294116.

The product of its digits is 653184000, while the sum is 66.

The spelling of 664555764666 in words is "six hundred sixty-four billion, five hundred fifty-five million, seven hundred sixty-four thousand, six hundred sixty-six".