19101727681 has 3 divisors (see below), whose sum is σ = 19101865891. Its totient is φ = 19101589472.

The previous prime is 19101727669. The next prime is 19101727709. The reversal of 19101727681 is 18672710191.

The square root of 19101727681 is 138209.

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., 5922687681 + 13179040000 = 76959^2 + 114800^2 .

It is not a de Polignac number, because 19101727681 - 2⁵ = 19101727649 is a prime.

It is a super-2 number, since 2×19101727681² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19101727621) 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, 69105 + ... + 207313.

Almost surely, 2^19101727681 is an apocalyptic number.

19101727681 is the 138209-th square number.

19101727681 is the 69105-th centered octagonal number.

It is an amenable number.

19101727681 is a deficient number, since it is larger than the sum of its proper divisors (138210).

19101727681 is an frugal number, since it uses more digits than its factorization.

19101727681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276418 (or 138209 counting only the distinct ones).

The product of its (nonzero) digits is 42336, while the sum is 43.

The spelling of 19101727681 in words is "nineteen billion, one hundred one million, seven hundred twenty-seven thousand, six hundred eighty-one".