321128545 has 4 divisors (see below), whose sum is σ = 385354260. Its totient is φ = 256902832.

The previous prime is 321128543. The next prime is 321128567. The reversal of 321128545 is 545821123.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 545821123 = 31 ⋅17607133.

It can be written as a sum of positive squares in 2 ways, for example, as 150773841 + 170354704 = 12279^2 + 13052^2 .

It is a cyclic number.

It is not a de Polignac number, because 321128545 - 2¹ = 321128543 is a prime.

It is not an unprimeable number, because it can be changed into a prime (321128543) 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, 32112850 + ... + 32112859.

It is an arithmetic number, because the mean of its divisors is an integer number (96338565).

Almost surely, 2^321128545 is an apocalyptic number.

It is an amenable number.

321128545 is a deficient number, since it is larger than the sum of its proper divisors (64225715).

321128545 is an equidigital number, since it uses as much as digits as its factorization.

321128545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64225714.

The product of its digits is 9600, while the sum is 31.

The square root of 321128545 is about 17920.0598492304. The cubic root of 321128545 is about 684.7935122734.

Adding to 321128545 its reverse (545821123), we get a palindrome (866949668).

The spelling of 321128545 in words is "three hundred twenty-one million, one hundred twenty-eight thousand, five hundred forty-five".