668980 has 48 divisors (see below), whose sum is σ = 1580544. Its totient is φ = 236160.

The previous prime is 668963. The next prime is 668989. The reversal of 668980 is 89866.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668989) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8019 + ... + 8101.

It is an arithmetic number, because the mean of its divisors is an integer number (32928).

2⁶⁶⁸⁹⁸⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 668980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (790272).

668980 is an abundant number, since it is smaller than the sum of its proper divisors (911564).

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

668980 is a wasteful number, since it uses less digits than its factorization.

668980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136 (or 134 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 668980 is about 817.9119757040. The cubic root of 668980 is about 87.4589739644.

It can be divided in two parts, 6 and 68980, that added together give a palindrome (68986).

The spelling of 668980 in words is "six hundred sixty-eight thousand, nine hundred eighty".