668323656 has 384 divisors, whose sum is σ = 2520403200. Its totient is φ = 159667200.

The previous prime is 668323633. The next prime is 668323661. The reversal of 668323656 is 656323866.

It is a super-3 number, since 3×668323656³ (a number of 27 digits) contains 333 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 (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2378236 + ... + 2378516.

It is an arithmetic number, because the mean of its divisors is an integer number (6563550).

Almost surely, 2^668323656 is an apocalyptic number.

668323656 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 668323656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1260201600).

668323656 is an abundant number, since it is smaller than the sum of its proper divisors (1852079544).

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

668323656 is a wasteful number, since it uses less digits than its factorization.

668323656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 338 (or 317 counting only the distinct ones).

The product of its digits is 933120, while the sum is 45.

The square root of 668323656 is about 25851.9565217026. The cubic root of 668323656 is about 874.3036226902.

The spelling of 668323656 in words is "six hundred sixty-eight million, three hundred twenty-three thousand, six hundred fifty-six".