19209838707409 has 45 divisors (see below), whose sum is σ = 23432887813083. Its totient is φ = 15745631622336.

The previous prime is 19209838707407. The next prime is 19209838707419. The reversal of 19209838707409 is 90470783890291.

The square root of 19209838707409 is 4382903.

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

It can be written as a sum of positive squares in only one way, i.e., 13924069861009 + 5285768846400 = 3731497^2 + 2299080^2 .

It is not a de Polignac number, because 19209838707409 - 2¹ = 19209838707407 is a prime.

It is a super-2 number, since 2×19209838707409² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (19209838707407) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 4939529737 + ... + 4939533625.

Almost surely, 2^{19209838707409} is an apocalyptic number.

19209838707409 is the 4382903-rd square number.

19209838707409 is the 2191452-nd centered octagonal number.

It is an amenable number.

19209838707409 is a deficient number, since it is larger than the sum of its proper divisors (4223049105674).

19209838707409 is an frugal number, since it uses more digits than its factorization.

19209838707409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7852 (or 3919 counting only the distinct ones).

The product of its (nonzero) digits is 54867456, while the sum is 67.

The spelling of 19209838707409 in words is "nineteen trillion, two hundred nine billion, eight hundred thirty-eight million, seven hundred seven thousand, four hundred nine".