19835039961509 has 4 divisors (see below), whose sum is σ = 20010571288716. Its totient is φ = 19659508634304.

The previous prime is 19835039961479. The next prime is 19835039961547. The reversal of 19835039961509 is 90516993053891.

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 163198224484 + 19671841737025 = 403978^2 + 4435295^2 .

It is a cyclic number.

It is not a de Polignac number, because 19835039961509 - 2¹⁶ = 19835039895973 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 (19835039961589) 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 3 ways as a sum of consecutive naturals, for example, 87765663434 + ... + 87765663659.

It is an arithmetic number, because the mean of its divisors is an integer number (5002642822179).

Almost surely, 2^{19835039961509} is an apocalyptic number.

It is an amenable number.

19835039961509 is a deficient number, since it is larger than the sum of its proper divisors (175531327207).

19835039961509 is a wasteful number, since it uses less digits than its factorization.

19835039961509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175531327206.

The product of its (nonzero) digits is 70858800, while the sum is 68.

The spelling of 19835039961509 in words is "nineteen trillion, eight hundred thirty-five billion, thirty-nine million, nine hundred sixty-one thousand, five hundred nine".