668441780 has 24 divisors (see below), whose sum is σ = 1405472040. Its totient is φ = 267044480.

The previous prime is 668441773. The next prime is 668441827. The reversal of 668441780 is 87144866.

It can be written as a sum of positive squares in 4 ways, for example, as 7540516 + 660901264 = 2746^2 + 25708^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3935 + ... + 36774.

It is an arithmetic number, because the mean of its divisors is an integer number (58561335).

Almost surely, 2^668441780 is an apocalyptic number.

It is an amenable number.

668441780 is an abundant number, since it is smaller than the sum of its proper divisors (737030260).

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

668441780 is a wasteful number, since it uses less digits than its factorization.

668441780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41539 (or 41537 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 44.

The square root of 668441780 is about 25854.2410447493. The cubic root of 668441780 is about 874.3551297488.

The spelling of 668441780 in words is "six hundred sixty-eight million, four hundred forty-one thousand, seven hundred eighty".