19678638536 has 8 divisors (see below), whose sum is σ = 36897447270. Its totient is φ = 9839319264.

The previous prime is 19678638527. The next prime is 19678638557. The reversal of 19678638536 is 63583687691.

It can be written as a sum of positive squares in only one way, i.e., 13925416036 + 5753222500 = 118006^2 + 75850^2 .

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, 1229914901 + ... + 1229914916.

Almost surely, 2^19678638536 is an apocalyptic number.

It is an amenable number.

19678638536 is a deficient number, since it is larger than the sum of its proper divisors (17218808734).

19678638536 is a wasteful number, since it uses less digits than its factorization.

19678638536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2459829823 (or 2459829819 counting only the distinct ones).

The product of its digits is 39191040, while the sum is 62.

The spelling of 19678638536 in words is "nineteen billion, six hundred seventy-eight million, six hundred thirty-eight thousand, five hundred thirty-six".