43128109 has 2 divisors, whose sum is σ = 43128110. Its totient is φ = 43128108.

The previous prime is 43128103. The next prime is 43128179. The reversal of 43128109 is 90182134.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 40678884 + 2449225 = 6378^2 + 1565^2 .

It is a cyclic number.

It is not a de Polignac number, because 43128109 - 2⁵ = 43128077 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43128103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21564054 + 21564055.

It is an arithmetic number, because the mean of its divisors is an integer number (21564055).

Almost surely, 2^43128109 is an apocalyptic number.

It is an amenable number.

43128109 is a deficient number, since it is larger than the sum of its proper divisors (1).

43128109 is an equidigital number, since it uses as much as digits as its factorization.

43128109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 43128109 is about 6567.1994792301. The cubic root of 43128109 is about 350.6873811096.

It can be divided in two parts, 4312 and 8109, that added together give a palindrome (12421).

The spelling of 43128109 in words is "forty-three million, one hundred twenty-eight thousand, one hundred nine".