1668393216 has 432 divisors, whose sum is σ = 5877301248. Its totient is φ = 445132800.

The previous prime is 1668393151. The next prime is 1668393239. The reversal of 1668393216 is 6123938661.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 23498461 + ... + 23498531.

It is an arithmetic number, because the mean of its divisors is an integer number (13604864).

Almost surely, 2^1668393216 is an apocalyptic number.

1668393216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1668393216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2938650624).

1668393216 is an abundant number, since it is smaller than the sum of its proper divisors (4208908032).

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

1668393216 is a wasteful number, since it uses less digits than its factorization.

1668393216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178 (or 161 counting only the distinct ones).

The product of its digits is 279936, while the sum is 45.

The square root of 1668393216 is about 40845.9693972367. The cubic root of 1668393216 is about 1186.0403703222.

The spelling of 1668393216 in words is "one billion, six hundred sixty-eight million, three hundred ninety-three thousand, two hundred sixteen".