646396128000 has 864 divisors, whose sum is σ = 2744209907712. Its totient is φ = 142967808000.

The previous prime is 646396127983. The next prime is 646396128013. The reversal of 646396128000 is 821693646.

646396128000 is a `hidden beast` number, since 6 + 4 + 639 + 6 + 1 + 2 + 8 + 0 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 62490829 + ... + 62501171.

Almost surely, 2^646396128000 is an apocalyptic number.

646396128000 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 646396128000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1372104953856).

646396128000 is an abundant number, since it is smaller than the sum of its proper divisors (2097813779712).

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

646396128000 is a wasteful number, since it uses less digits than its factorization.

646396128000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10418 (or 10391 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 45.

The spelling of 646396128000 in words is "six hundred forty-six billion, three hundred ninety-six million, one hundred twenty-eight thousand".