668286446420 has 24 divisors (see below), whose sum is σ = 1406445811848. Its totient is φ = 266734716800.

The previous prime is 668286446363. The next prime is 668286446441. The reversal of 668286446420 is 24644682866.

It can be written as a sum of positive squares in 4 ways, for example, as 62806374544 + 605480071876 = 250612^2 + 778126^2 .

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 36231911 + ... + 36250350.

It is an arithmetic number, because the mean of its divisors is an integer number (58601908827).

Almost surely, 2^668286446420 is an apocalyptic number.

It is an amenable number.

668286446420 is an abundant number, since it is smaller than the sum of its proper divisors (738159365428).

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

668286446420 is a wasteful number, since it uses less digits than its factorization.

668286446420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72482731 (or 72482729 counting only the distinct ones).

The product of its (nonzero) digits is 21233664, while the sum is 56.

The spelling of 668286446420 in words is "six hundred sixty-eight billion, two hundred eighty-six million, four hundred forty-six thousand, four hundred twenty".