19386209891 has 4 divisors (see below), whose sum is σ = 19396707792. Its totient is φ = 19375711992.

The previous prime is 19386209881. The next prime is 19386209957. The reversal of 19386209891 is 19890268391.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19386209891 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19386209851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5246180 + ... + 5249873.

It is an arithmetic number, because the mean of its divisors is an integer number (4849176948).

Almost surely, 2^19386209891 is an apocalyptic number.

19386209891 is a deficient number, since it is larger than the sum of its proper divisors (10497901).

19386209891 is a wasteful number, since it uses less digits than its factorization.

19386209891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10497900.

The product of its (nonzero) digits is 1679616, while the sum is 56.

The spelling of 19386209891 in words is "nineteen billion, three hundred eighty-six million, two hundred nine thousand, eight hundred ninety-one".