19961289169 has 4 divisors (see below), whose sum is σ = 19961579520. Its totient is φ = 19960998820.

The previous prime is 19961289149. The next prime is 19961289203. The reversal of 19961289169 is 96198216991.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 19961289169 - 2²⁷ = 19827071441 is a prime.

It is a super-2 number, since 2×19961289169² (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 (19961289149) 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, 22512 + ... + 201070.

It is an arithmetic number, because the mean of its divisors is an integer number (4990394880).

Almost surely, 2^19961289169 is an apocalyptic number.

It is an amenable number.

19961289169 is a deficient number, since it is larger than the sum of its proper divisors (290351).

19961289169 is a wasteful number, since it uses less digits than its factorization.

19961289169 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290350.

The product of its digits is 3779136, while the sum is 61.

The spelling of 19961289169 in words is "nineteen billion, nine hundred sixty-one million, two hundred eighty-nine thousand, one hundred sixty-nine".