128643329 has 2 divisors, whose sum is σ = 128643330. Its totient is φ = 128643328.

The previous prime is 128643323. The next prime is 128643337. The reversal of 128643329 is 923346821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71791729 + 56851600 = 8473^2 + 7540^2 .

It is an emirp because it is prime and its reverse (923346821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 128643329 - 2¹² = 128639233 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 128643292 and 128643301.

It is not a weakly prime, because it can be changed into another prime (128643323) 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, 64321664 + 64321665.

It is an arithmetic number, because the mean of its divisors is an integer number (64321665).

Almost surely, 2^128643329 is an apocalyptic number.

It is an amenable number.

128643329 is a deficient number, since it is larger than the sum of its proper divisors (1).

128643329 is an equidigital number, since it uses as much as digits as its factorization.

128643329 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 62208, while the sum is 38.

The square root of 128643329 is about 11342.1042580290. The cubic root of 128643329 is about 504.8113257861.

The spelling of 128643329 in words is "one hundred twenty-eight million, six hundred forty-three thousand, three hundred twenty-nine".