668471616 has 168 divisors, whose sum is σ = 2027005344. Its totient is φ = 218350080.

The previous prime is 668471599. The next prime is 668471627. The reversal of 668471616 is 616174866.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 823851 + ... + 824661.

It is an arithmetic number, because the mean of its divisors is an integer number (12065508).

Almost surely, 2^668471616 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 668471616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1013502672).

668471616 is an abundant number, since it is smaller than the sum of its proper divisors (1358533728).

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

668471616 is an equidigital number, since it uses as much as digits as its factorization.

668471616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 891 (or 869 counting only the distinct ones).

The product of its digits is 290304, while the sum is 45.

The square root of 668471616 is about 25854.8180422915. The cubic root of 668471616 is about 874.3681385465.

The spelling of 668471616 in words is "six hundred sixty-eight million, four hundred seventy-one thousand, six hundred sixteen".