668814408 has 160 divisors (see below), whose sum is σ = 2005284600. Its totient is φ = 207525888.

The previous prime is 668814403. The next prime is 668814439. The reversal of 668814408 is 804418866.

668814408 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 573985764 + 94828644 = 23958^2 + 9738^2 .

It is not an unprimeable number, because it can be changed into a prime (668814403) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1200466 + ... + 1201022.

Almost surely, 2^668814408 is an apocalyptic number.

668814408 is a gapful number since it is divisible by the number (68) 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 668814408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1002642300).

668814408 is an abundant number, since it is smaller than the sum of its proper divisors (1336470192).

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

668814408 is a wasteful number, since it uses less digits than its factorization.

668814408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 701 (or 688 counting only the distinct ones).

The product of its (nonzero) digits is 294912, while the sum is 45.

The square root of 668814408 is about 25861.4463632644. The cubic root of 668814408 is about 874.5175715601.

It can be divided in two parts, 66881 and 4408, that added together give a square (71289 = 267²).

The spelling of 668814408 in words is "six hundred sixty-eight million, eight hundred fourteen thousand, four hundred eight".