128290321 has 4 divisors (see below), whose sum is σ = 128898544. Its totient is φ = 127682100.

The previous prime is 128290277. The next prime is 128290333. The reversal of 128290321 is 123092821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 128290321 - 2²⁵ = 94735889 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 128290321.

It is not an unprimeable number, because it can be changed into a prime (128294321) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 303795 + ... + 304216.

It is an arithmetic number, because the mean of its divisors is an integer number (32224636).

Almost surely, 2^128290321 is an apocalyptic number.

It is an amenable number.

128290321 is a deficient number, since it is larger than the sum of its proper divisors (608223).

128290321 is an equidigital number, since it uses as much as digits as its factorization.

128290321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 608222.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 128290321 is about 11326.5317286449. The cubic root of 128290321 is about 504.3491546872.

The spelling of 128290321 in words is "one hundred twenty-eight million, two hundred ninety thousand, three hundred twenty-one".