42128869 has 2 divisors, whose sum is σ = 42128870. Its totient is φ = 42128868.

The previous prime is 42128831. The next prime is 42128887. The reversal of 42128869 is 96882124.

42128869 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38750625 + 3378244 = 6225^2 + 1838^2 .

It is a cyclic number.

It is not a de Polignac number, because 42128869 - 2⁷ = 42128741 is a prime.

It is a super-2 number, since 2×42128869² = 3549683206438322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42128809) 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, 21064434 + 21064435.

It is an arithmetic number, because the mean of its divisors is an integer number (21064435).

Almost surely, 2^42128869 is an apocalyptic number.

It is an amenable number.

42128869 is a deficient number, since it is larger than the sum of its proper divisors (1).

42128869 is an equidigital number, since it uses as much as digits as its factorization.

42128869 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 55296, while the sum is 40.

The square root of 42128869 is about 6490.6755426535. The cubic root of 42128869 is about 347.9578190166.

The spelling of 42128869 in words is "forty-two million, one hundred twenty-eight thousand, eight hundred sixty-nine".