9919971738 has 24 divisors (see below), whose sum is σ = 21585527028. Its totient is φ = 3292464192.

The previous prime is 9919971713. The next prime is 9919971757. The reversal of 9919971738 is 8371799199.

It can be written as a sum of positive squares in 2 ways, for example, as 9730441449 + 189530289 = 98643^2 + 13767^2 .

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, 1178445 + ... + 1186832.

Almost surely, 2^9919971738 is an apocalyptic number.

9919971738 is an abundant number, since it is smaller than the sum of its proper divisors (11665555290).

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

9919971738 is a wasteful number, since it uses less digits than its factorization.

9919971738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2365518 (or 2365515 counting only the distinct ones).

The product of its digits is 7715736, while the sum is 63.

The square root of 9919971738 is about 99599.0549051546. The cubic root of 9919971738 is about 2148.6721014576.

The spelling of 9919971738 in words is "nine billion, nine hundred nineteen million, nine hundred seventy-one thousand, seven hundred thirty-eight".