128215489 has 2 divisors, whose sum is σ = 128215490. Its totient is φ = 128215488.

The previous prime is 128215457. The next prime is 128215511. The reversal of 128215489 is 984512821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 104857600 + 23357889 = 10240^2 + 4833^2 .

It is a cyclic number.

It is not a de Polignac number, because 128215489 - 2⁵ = 128215457 is a prime.

It is a Chen prime.

It is equal to p_7282579 and since 128215489 and 7282579 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (128215429) 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 as a sum of consecutive naturals, namely, 64107744 + 64107745.

It is an arithmetic number, because the mean of its divisors is an integer number (64107745).

Almost surely, 2^128215489 is an apocalyptic number.

It is an amenable number.

128215489 is a deficient number, since it is larger than the sum of its proper divisors (1).

128215489 is an equidigital number, since it uses as much as digits as its factorization.

128215489 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 46080, while the sum is 40.

The square root of 128215489 is about 11323.2278525163. The cubic root of 128215489 is about 504.2510729918.

The spelling of 128215489 in words is "one hundred twenty-eight million, two hundred fifteen thousand, four hundred eighty-nine".