128321564 has 12 divisors (see below), whose sum is σ = 256643184. Its totient is φ = 54994944.

The previous prime is 128321551. The next prime is 128321597. The reversal of 128321564 is 465123821.

128321564 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 128321564.

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 2291429 + ... + 2291484.

It is an arithmetic number, because the mean of its divisors is an integer number (21386932).

Almost surely, 2^128321564 is an apocalyptic number.

128321564 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

128321564 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

128321564 is a wasteful number, since it uses less digits than its factorization.

128321564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4582924 (or 4582922 counting only the distinct ones).

The product of its digits is 11520, while the sum is 32.

The square root of 128321564 is about 11327.9108400446. The cubic root of 128321564 is about 504.3900933476.

The spelling of 128321564 in words is "one hundred twenty-eight million, three hundred twenty-one thousand, five hundred sixty-four".