668404220 has 24 divisors (see below), whose sum is σ = 1531253808. Its totient is φ = 243056000.

The previous prime is 668404213. The next prime is 668404259. The reversal of 668404220 is 22404866.

It is a happy number.

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, 1518881 + ... + 1519320.

It is an arithmetic number, because the mean of its divisors is an integer number (63802242).

Almost surely, 2^668404220 is an apocalyptic number.

It is an amenable number.

668404220 is an abundant number, since it is smaller than the sum of its proper divisors (862849588).

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

668404220 is a wasteful number, since it uses less digits than its factorization.

668404220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3038221 (or 3038219 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 32.

The square root of 668404220 is about 25853.5146546848. The cubic root of 668404220 is about 874.3387526587.

The spelling of 668404220 in words is "six hundred sixty-eight million, four hundred four thousand, two hundred twenty".