9964378638 has 24 divisors (see below), whose sum is σ = 21791262168. Its totient is φ = 3290417232.

The previous prime is 9964378583. The next prime is 9964378651. The reversal of 9964378638 is 8368734699.

9964378638 is a `hidden beast` number, since 9 + 96 + 437 + 86 + 38 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2584881 + ... + 2588732.

It is an arithmetic number, because the mean of its divisors is an integer number (907969257).

Almost surely, 2^9964378638 is an apocalyptic number.

9964378638 is an abundant number, since it is smaller than the sum of its proper divisors (11826883530).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

9964378638 is a wasteful number, since it uses less digits than its factorization.

9964378638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5173728 (or 5173725 counting only the distinct ones).

The product of its digits is 47029248, while the sum is 63.

The square root of 9964378638 is about 99821.7342966951. The cubic root of 9964378638 is about 2151.8735166041.

The spelling of 9964378638 in words is "nine billion, nine hundred sixty-four million, three hundred seventy-eight thousand, six hundred thirty-eight".