42128794009 has 3 divisors (see below), whose sum is σ = 42128999263. Its totient is φ = 42128588756.

The previous prime is 42128793953. The next prime is 42128794013. The reversal of 42128794009 is 90049782124.

The square root of 42128794009 is 205253.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 7766015625 + 34362778384 = 88125^2 + 185372^2 .

It is not a de Polignac number, because 42128794009 - 2²⁵ = 42095239577 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 42128794009.

It is not an unprimeable number, because it can be changed into a prime (42128794049) 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 in 2 ways as a sum of consecutive naturals, for example, 102627 + ... + 307879.

Almost surely, 2^42128794009 is an apocalyptic number.

42128794009 is the 205253-rd square number.

42128794009 is the 102627-th centered octagonal number.

It is an amenable number.

42128794009 is a deficient number, since it is larger than the sum of its proper divisors (205254).

42128794009 is an frugal number, since it uses more digits than its factorization.

42128794009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410506 (or 205253 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 46.

The spelling of 42128794009 in words is "forty-two billion, one hundred twenty-eight million, seven hundred ninety-four thousand, nine".