668618320 has 80 divisors (see below), whose sum is σ = 1600290432. Its totient is φ = 259683840.

The previous prime is 668618311. The next prime is 668618329. The reversal of 668618320 is 23816866.

668618320 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (668618311) and next prime (668618329).

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668618329) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 435955 + ... + 437485.

Almost surely, 2^668618320 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 668618320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (800145216).

668618320 is an abundant number, since it is smaller than the sum of its proper divisors (931672112).

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

668618320 is a wasteful number, since it uses less digits than its factorization.

668618320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1700 (or 1694 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 40.

The square root of 668618320 is about 25857.6549594119. The cubic root of 668618320 is about 874.4320973433.

The spelling of 668618320 in words is "six hundred sixty-eight million, six hundred eighteen thousand, three hundred twenty".