321680128 has 72 divisors (see below), whose sum is σ = 800593920. Its totient is φ = 125322240.

The previous prime is 321680113. The next prime is 321680141. The reversal of 321680128 is 821086123.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 321680128.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 11553 + ... + 27871.

It is an arithmetic number, because the mean of its divisors is an integer number (11119360).

Almost surely, 2^321680128 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 321680128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (400296960).

321680128 is an abundant number, since it is smaller than the sum of its proper divisors (478913792).

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

321680128 is a wasteful number, since it uses less digits than its factorization.

321680128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16353 (or 16339 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 31.

The square root of 321680128 is about 17935.4433455100. The cubic root of 321680128 is about 685.1853640820.

The spelling of 321680128 in words is "three hundred twenty-one million, six hundred eighty thousand, one hundred twenty-eight".