9999538 has 4 divisors (see below), whose sum is σ = 14999310. Its totient is φ = 4999768.

The previous prime is 9999533. The next prime is 9999593. The reversal of 9999538 is 8359999.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8359999 = 389 ⋅21491.

It can be written as a sum of positive squares in only one way, i.e., 6416089 + 3583449 = 2533^2 + 1893^2 .

It is not an unprimeable number, because it can be changed into a prime (9999533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2499883 + ... + 2499886.

Almost surely, 2^9999538 is an apocalyptic number.

9999538 is a deficient number, since it is larger than the sum of its proper divisors (4999772).

9999538 is a wasteful number, since it uses less digits than its factorization.

9999538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4999771.

The product of its digits is 787320, while the sum is 52.

The square root of 9999538 is about 3162.2046107107. The cubic root of 9999538 is about 215.4401511227.

The spelling of 9999538 in words is "nine million, nine hundred ninety-nine thousand, five hundred thirty-eight".