19699565128 has 8 divisors (see below), whose sum is σ = 36936684630. Its totient is φ = 9849782560.

The previous prime is 19699565089. The next prime is 19699565153. The reversal of 19699565128 is 82156599691.

It can be written as a sum of positive squares in only one way, i.e., 17009898084 + 2689667044 = 130422^2 + 51862^2 .

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, 1231222813 + ... + 1231222828.

Almost surely, 2^19699565128 is an apocalyptic number.

It is an amenable number.

19699565128 is a deficient number, since it is larger than the sum of its proper divisors (17237119502).

19699565128 is a wasteful number, since it uses less digits than its factorization.

19699565128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2462445647 (or 2462445643 counting only the distinct ones).

The product of its digits is 10497600, while the sum is 61.

The spelling of 19699565128 in words is "nineteen billion, six hundred ninety-nine million, five hundred sixty-five thousand, one hundred twenty-eight".