19127719809 has 75 divisors (see below), whose sum is σ = 31680097185. Its totient is φ = 11501277480.

The previous prime is 19127719759. The next prime is 19127719823. The reversal of 19127719809 is 90891772191.

The square root of 19127719809 is 138303.

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

It is not a de Polignac number, because 19127719809 - 2¹¹ = 19127717761 is a prime.

It is a super-2 number, since 2×19127719809² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (19127719829) by changing a digit.

It is a polite number, since it can be written in 74 ways as a sum of consecutive naturals, for example, 150611904 + ... + 150612030.

Almost surely, 2^19127719809 is an apocalyptic number.

19127719809 is the 138303-rd square number.

19127719809 is the 69152-nd centered octagonal number.

It is an amenable number.

19127719809 is a deficient number, since it is larger than the sum of its proper divisors (12552377376).

19127719809 is an frugal number, since it uses more digits than its factorization.

19127719809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 310 (or 141 counting only the distinct ones).

The product of its (nonzero) digits is 571536, while the sum is 54.

The spelling of 19127719809 in words is "nineteen billion, one hundred twenty-seven million, seven hundred nineteen thousand, eight hundred nine".