668416 has 36 divisors (see below), whose sum is σ = 1528912. Its totient is φ = 285696.

The previous prime is 668407. The next prime is 668417. The reversal of 668416 is 614866.

It is a nialpdrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668417) by changing a digit.

668416 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1606 + ... + 1978.

2⁶⁶⁸⁴¹⁶ 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 668416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (764456).

668416 is an abundant number, since it is smaller than the sum of its proper divisors (860496).

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

668416 is an equidigital number, since it uses as much as digits as its factorization.

668416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 396 (or 382 counting only the distinct ones).

The product of its digits is 6912, while the sum is 31.

The square root of 668416 is about 817.5671226266. The cubic root of 668416 is about 87.4343889096.

The spelling of 668416 in words is "six hundred sixty-eight thousand, four hundred sixteen".