668844544 has 40 divisors (see below), whose sum is σ = 1352569680. Its totient is φ = 330372096.

The previous prime is 668844541. The next prime is 668844551. The reversal of 668844544 is 445448866.

It is not an unprimeable number, because it can be changed into a prime (668844541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34627 + ... + 50365.

It is an arithmetic number, because the mean of its divisors is an integer number (33814242).

Almost surely, 2^668844544 is an apocalyptic number.

668844544 is a gapful number since it is divisible by the number (64) 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 668844544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (676284840).

668844544 is an abundant number, since it is smaller than the sum of its proper divisors (683725136).

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

668844544 is an equidigital number, since it uses as much as digits as its factorization.

668844544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15840 (or 15824 counting only the distinct ones).

The product of its digits is 2949120, while the sum is 49.

The square root of 668844544 is about 25862.0290000611. The cubic root of 668844544 is about 874.5307062780.

The spelling of 668844544 in words is "six hundred sixty-eight million, eight hundred forty-four thousand, five hundred forty-four".