19040520237509 has 4 divisors (see below), whose sum is σ = 19209020416716. Its totient is φ = 18872020058304.

The previous prime is 19040520237491. The next prime is 19040520237511. The reversal of 19040520237509 is 90573202504091.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5487409320484 + 13553110917025 = 2342522^2 + 3681455^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19040520237509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19040520237559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 84250089434 + ... + 84250089659.

It is an arithmetic number, because the mean of its divisors is an integer number (4802255104179).

Almost surely, 2^{19040520237509} is an apocalyptic number.

It is an amenable number.

19040520237509 is a deficient number, since it is larger than the sum of its proper divisors (168500179207).

19040520237509 is a wasteful number, since it uses less digits than its factorization.

19040520237509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168500179206.

The product of its (nonzero) digits is 680400, while the sum is 47.

The spelling of 19040520237509 in words is "nineteen trillion, forty billion, five hundred twenty million, two hundred thirty-seven thousand, five hundred nine".