668649168 has 400 divisors, whose sum is σ = 2333422080. Its totient is φ = 182476800.

The previous prime is 668649133. The next prime is 668649181. The reversal of 668649168 is 861946866.

It is a Harshad number since it is a multiple of its sum of digits (54).

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 79 ways as a sum of consecutive naturals, for example, 7512868 + ... + 7512956.

Almost surely, 2^668649168 is an apocalyptic number.

668649168 is a gapful number since it is divisible by the number (68) 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 668649168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1166711040).

668649168 is an abundant number, since it is smaller than the sum of its proper divisors (1664772912).

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

668649168 is a wasteful number, since it uses less digits than its factorization.

668649168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168 (or 153 counting only the distinct ones).

The product of its digits is 2985984, while the sum is 54.

The square root of 668649168 is about 25858.2514490056. The cubic root of 668649168 is about 874.4455450088.

The spelling of 668649168 in words is "six hundred sixty-eight million, six hundred forty-nine thousand, one hundred sixty-eight".