646597996128 has 216 divisors, whose sum is σ = 2140380070920. Its totient is φ = 184620441600.

The previous prime is 646597996103. The next prime is 646597996147. The reversal of 646597996128 is 821699795646.

646597996128 is a `hidden beast` number, since 6 + 4 + 6 + 597 + 9 + 9 + 6 + 1 + 28 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 22579003 + ... + 22607621.

It is an arithmetic number, because the mean of its divisors is an integer number (9909166995).

Almost surely, 2^646597996128 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 646597996128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1070190035460).

646597996128 is an abundant number, since it is smaller than the sum of its proper divisors (1493782074792).

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

646597996128 is a wasteful number, since it uses less digits than its factorization.

646597996128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30250 (or 30232 counting only the distinct ones).

The product of its digits is 352719360, while the sum is 72.

The spelling of 646597996128 in words is "six hundred forty-six billion, five hundred ninety-seven million, nine hundred ninety-six thousand, one hundred twenty-eight".