128809069 has 2 divisors, whose sum is σ = 128809070. Its totient is φ = 128809068.

The previous prime is 128809049. The next prime is 128809073. The reversal of 128809069 is 960908821.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 113167044 + 15642025 = 10638^2 + 3955^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128809069 is a prime.

It is a super-2 number, since 2×128809069² = 33183552513293522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128809049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64404534 + 64404535.

It is an arithmetic number, because the mean of its divisors is an integer number (64404535).

Almost surely, 2^128809069 is an apocalyptic number.

It is an amenable number.

128809069 is a deficient number, since it is larger than the sum of its proper divisors (1).

128809069 is an equidigital number, since it uses as much as digits as its factorization.

128809069 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 62208, while the sum is 43.

The square root of 128809069 is about 11349.4083105684. The cubic root of 128809069 is about 505.0280270691.

The spelling of 128809069 in words is "one hundred twenty-eight million, eight hundred nine thousand, sixty-nine".