19808169869 has 4 divisors (see below), whose sum is σ = 19841239200. Its totient is φ = 19775100540.

The previous prime is 19808169863. The next prime is 19808169929. The reversal of 19808169869 is 96896180891.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 19808169869 - 2⁸ = 19808169613 is a prime.

It is a super-2 number, since 2×19808169869² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19808169863) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16533767 + ... + 16534964.

It is an arithmetic number, because the mean of its divisors is an integer number (4960309800).

Almost surely, 2^19808169869 is an apocalyptic number.

It is an amenable number.

19808169869 is a deficient number, since it is larger than the sum of its proper divisors (33069331).

19808169869 is an equidigital number, since it uses as much as digits as its factorization.

19808169869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33069330.

The product of its (nonzero) digits is 13436928, while the sum is 65.

The spelling of 19808169869 in words is "nineteen billion, eight hundred eight million, one hundred sixty-nine thousand, eight hundred sixty-nine".