19549680891 has 16 divisors (see below), whose sum is σ = 28104140064. Its totient is φ = 12016514304.

The previous prime is 19549680889. The next prime is 19549680929. The reversal of 19549680891 is 19808694591.

It is not a de Polignac number, because 19549680891 - 2¹ = 19549680889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19549680851) 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 15 ways as a sum of consecutive naturals, for example, 259036 + ... + 325881.

It is an arithmetic number, because the mean of its divisors is an integer number (1756508754).

Almost surely, 2^19549680891 is an apocalyptic number.

19549680891 is a deficient number, since it is larger than the sum of its proper divisors (8554459173).

19549680891 is a wasteful number, since it uses less digits than its factorization.

19549680891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 585790.

The product of its (nonzero) digits is 5598720, while the sum is 60.

The spelling of 19549680891 in words is "nineteen billion, five hundred forty-nine million, six hundred eighty thousand, eight hundred ninety-one".