19659779881 has 4 divisors (see below), whose sum is σ = 22468319872. Its totient is φ = 16851239892.

The previous prime is 19659779873. The next prime is 19659779899. The reversal of 19659779881 is 18897795691.

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 19659779881 - 2³ = 19659779873 is a prime.

It is a super-2 number, since 2×19659779881² (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 19659779881.

It is not an unprimeable number, because it can be changed into a prime (19659779801) 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 3 ways as a sum of consecutive naturals, for example, 1404269985 + ... + 1404269998.

It is an arithmetic number, because the mean of its divisors is an integer number (5617079968).

Almost surely, 2^19659779881 is an apocalyptic number.

It is an amenable number.

19659779881 is a deficient number, since it is larger than the sum of its proper divisors (2808539991).

19659779881 is an equidigital number, since it uses as much as digits as its factorization.

19659779881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2808539990.

The product of its digits is 68584320, while the sum is 70.

The spelling of 19659779881 in words is "nineteen billion, six hundred fifty-nine million, seven hundred seventy-nine thousand, eight hundred eighty-one".