128623321 has 4 divisors (see below), whose sum is σ = 128646144. Its totient is φ = 128600500.

The previous prime is 128623307. The next prime is 128623333. The reversal of 128623321 is 123326821.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 128623321 - 2⁵ = 128623289 is a prime.

It is a super-3 number, since 3×128623321³ (a number of 25 digits) contains 333 as substring.

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 128623321.

It is not an unprimeable number, because it can be changed into a prime (128626321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3816 + ... + 16486.

It is an arithmetic number, because the mean of its divisors is an integer number (32161536).

Almost surely, 2^128623321 is an apocalyptic number.

It is an amenable number.

128623321 is a deficient number, since it is larger than the sum of its proper divisors (22823).

128623321 is a wasteful number, since it uses less digits than its factorization.

128623321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22822.

The product of its digits is 3456, while the sum is 28.

The square root of 128623321 is about 11341.2222004509. Note that the first 4 decimals coincide. The cubic root of 128623321 is about 504.7851531926.

The spelling of 128623321 in words is "one hundred twenty-eight million, six hundred twenty-three thousand, three hundred twenty-one".