668344320000 has 1530 divisors, whose sum is σ = 2882434527258. Its totient is φ = 148635648000.

The previous prime is 668344319959. The next prime is 668344320019. The reversal of 668344320000 is 23443866.

It is a happy number.

668344320000 is a `hidden beast` number, since 6 + 6 + 8 + 3 + 443 + 200 + 0 + 0 = 666.

It can be written as a sum of positive squares in 5 ways, for example, as 125894393856 + 542449926144 = 354816^2 + 736512^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 89 ways as a sum of consecutive naturals, for example, 18063359982 + ... + 18063360018.

Almost surely, 2^668344320000 is an apocalyptic number.

668344320000 is a gapful number since it is divisible by the number (60) 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 668344320000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1441217263629).

668344320000 is an abundant number, since it is smaller than the sum of its proper divisors (2214090207258).

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

668344320000 is an frugal number, since it uses more digits than its factorization.

668344320000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109 (or 54 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 36.

Adding to 668344320000 its reverse (23443866), we get a palindrome (668367763866).

It can be divided in two parts, 66834 and 4320000, that added together give a palindrome (4386834).

The spelling of 668344320000 in words is "six hundred sixty-eight billion, three hundred forty-four million, three hundred twenty thousand".