128023009 has 2 divisors, whose sum is σ = 128023010. Its totient is φ = 128023008.

The previous prime is 128023003. The next prime is 128023019. The reversal of 128023009 is 900320821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 82864609 + 45158400 = 9103^2 + 6720^2 .

It is an emirp because it is prime and its reverse (900320821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 128023009 - 2³ = 128023001 is a prime.

It is not a weakly prime, because it can be changed into another prime (128023001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64011504 + 64011505.

It is an arithmetic number, because the mean of its divisors is an integer number (64011505).

Almost surely, 2^128023009 is an apocalyptic number.

It is an amenable number.

128023009 is a deficient number, since it is larger than the sum of its proper divisors (1).

128023009 is an equidigital number, since it uses as much as digits as its factorization.

128023009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 128023009 is about 11314.7253170371. The cubic root of 128023009 is about 503.9986155690.

The spelling of 128023009 in words is "one hundred twenty-eight million, twenty-three thousand, nine".