19680489905 has 4 divisors (see below), whose sum is σ = 23616587892. Its totient is φ = 15744391920.

The previous prime is 19680489901. The next prime is 19680489931. The reversal of 19680489905 is 50998408691.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50998408691 = 23 ⋅2217322117.

It can be written as a sum of positive squares in 2 ways, for example, as 6958229056 + 12722260849 = 83416^2 + 112793^2 .

It is not a de Polignac number, because 19680489905 - 2² = 19680489901 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19680489901) 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, 1968048986 + ... + 1968048995.

It is an arithmetic number, because the mean of its divisors is an integer number (5904146973).

Almost surely, 2^19680489905 is an apocalyptic number.

It is an amenable number.

19680489905 is a deficient number, since it is larger than the sum of its proper divisors (3936097987).

19680489905 is an equidigital number, since it uses as much as digits as its factorization.

19680489905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3936097986.

The product of its (nonzero) digits is 5598720, while the sum is 59.

The spelling of 19680489905 in words is "nineteen billion, six hundred eighty million, four hundred eighty-nine thousand, nine hundred five".