19685821969 has 16 divisors (see below), whose sum is σ = 22453853184. Its totient is φ = 17083963600.

The previous prime is 19685821913. The next prime is 19685821999. The reversal of 19685821969 is 96912858691.

It is a de Polignac number, because none of the positive numbers 2^k-19685821969 is a prime.

It is a super-2 number, since 2×19685821969² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 19685821969.

It is not an unprimeable number, because it can be changed into a prime (19685821999) 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, 49914 + ... + 204604.

It is an arithmetic number, because the mean of its divisors is an integer number (1403365824).

Almost surely, 2^19685821969 is an apocalyptic number.

It is an amenable number.

19685821969 is a deficient number, since it is larger than the sum of its proper divisors (2768031215).

19685821969 is a wasteful number, since it uses less digits than its factorization.

19685821969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155228.

The product of its digits is 16796160, while the sum is 64.

The spelling of 19685821969 in words is "nineteen billion, six hundred eighty-five million, eight hundred twenty-one thousand, nine hundred sixty-nine".