646576128 has 192 divisors, whose sum is σ = 2091398400. Its totient is φ = 195747840.

The previous prime is 646576127. The next prime is 646576129. The reversal of 646576128 is 821675646.

646576128 is a `hidden beast` number, since 64 + 6 + 576 + 12 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (646576127) and next prime (646576129).

It is a tau number, because it is divible by the number of its divisors (192).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646576123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 607725 + ... + 608787.

It is an arithmetic number, because the mean of its divisors is an integer number (10892700).

Almost surely, 2^646576128 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 646576128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1045699200).

646576128 is an abundant number, since it is smaller than the sum of its proper divisors (1444822272).

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

646576128 is a wasteful number, since it uses less digits than its factorization.

646576128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1105 (or 1079 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The square root of 646576128 is about 25427.8612549306. The cubic root of 646576128 is about 864.7154567673.

The spelling of 646576128 in words is "six hundred forty-six million, five hundred seventy-six thousand, one hundred twenty-eight".