664168768 has 14 divisors (see below), whose sum is σ = 1317960026. Its totient is φ = 332084352.

The previous prime is 664168753. The next prime is 664168787. The reversal of 664168768 is 867861466.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 427993344 + 236175424 = 20688^2 + 15368^2 .

It is a super-2 number, since 2×664168768² = 882240304773275648, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5188755 + ... + 5188882.

Almost surely, 2^664168768 is an apocalyptic number.

It is an amenable number.

664168768 is a deficient number, since it is larger than the sum of its proper divisors (653791258).

664168768 is a wasteful number, since it uses less digits than its factorization.

664168768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10377649 (or 10377639 counting only the distinct ones).

The product of its digits is 2322432, while the sum is 52.

The square root of 664168768 is about 25771.4719796910. The cubic root of 664168768 is about 872.4880414778.

The spelling of 664168768 in words is "six hundred sixty-four million, one hundred sixty-eight thousand, seven hundred sixty-eight".