668691072 has 256 divisors, whose sum is σ = 2283494400. Its totient is φ = 188697600.

The previous prime is 668691061. The next prime is 668691091. The reversal of 668691072 is 270196866.

668691072 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3169047 + ... + 3169257.

It is an arithmetic number, because the mean of its divisors is an integer number (8919900).

Almost surely, 2^668691072 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 668691072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1141747200).

668691072 is an abundant number, since it is smaller than the sum of its proper divisors (1614803328).

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

668691072 is a wasteful number, since it uses less digits than its factorization.

668691072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 372 (or 354 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 668691072 is about 25859.0616999148. The cubic root of 668691072 is about 874.4638116886.

The spelling of 668691072 in words is "six hundred sixty-eight million, six hundred ninety-one thousand, seventy-two".