19718421896 has 8 divisors (see below), whose sum is σ = 36972041070. Its totient is φ = 9859210944.

The previous prime is 19718421887. The next prime is 19718421953. The reversal of 19718421896 is 69812481791.

It can be written as a sum of positive squares in only one way, i.e., 18329368996 + 1389052900 = 135386^2 + 37270^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1232401361 + ... + 1232401376.

Almost surely, 2^19718421896 is an apocalyptic number.

It is an amenable number.

19718421896 is a deficient number, since it is larger than the sum of its proper divisors (17253619174).

19718421896 is a wasteful number, since it uses less digits than its factorization.

19718421896 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2464802743 (or 2464802739 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 56.

The spelling of 19718421896 in words is "nineteen billion, seven hundred eighteen million, four hundred twenty-one thousand, eight hundred ninety-six".