646128000 has 384 divisors, whose sum is σ = 2656031040. Its totient is φ = 147456000.

The previous prime is 646127987. The next prime is 646128059. The reversal of 646128000 is 821646.

646128000 is a `hidden beast` number, since 646 + 12 + 8 + 0 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

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, 1007680 + ... + 1008320.

Almost surely, 2^646128000 is an apocalyptic number.

646128000 is a gapful number since it is divisible by the number (60) 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 646128000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1328015520).

646128000 is an abundant number, since it is smaller than the sum of its proper divisors (2009903040).

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

646128000 is a wasteful number, since it uses less digits than its factorization.

646128000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 683 (or 658 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 646128000 is about 25419.0479758782. The cubic root of 646128000 is about 864.5156387056.

Adding to 646128000 its reverse (821646), we get a palindrome (646949646).

The spelling of 646128000 in words is "six hundred forty-six million, one hundred twenty-eight thousand".