668783781800 has 24 divisors (see below), whose sum is σ = 1554922293150. Its totient is φ = 267513512640.

The previous prime is 668783781797. The next prime is 668783781823. The reversal of 668783781800 is 8187387866.

It can be written as a sum of positive squares in 3 ways, for example, as 296129695684 + 372654086116 = 544178^2 + 610454^2 .

It is a super-2 number, since 2×668783781800² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1671959255 + ... + 1671959654.

Almost surely, 2^668783781800 is an apocalyptic number.

It is an amenable number.

668783781800 is an abundant number, since it is smaller than the sum of its proper divisors (886138511350).

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

668783781800 is a wasteful number, since it uses less digits than its factorization.

668783781800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3343918925 (or 3343918916 counting only the distinct ones).

The product of its (nonzero) digits is 21676032, while the sum is 62.

The spelling of 668783781800 in words is "six hundred sixty-eight billion, seven hundred eighty-three million, seven hundred eighty-one thousand, eight hundred".