9999999873 has 6 divisors (see below), whose sum is σ = 14444444274. Its totient is φ = 6666666576.

The previous prime is 9999999851. The next prime is 9999999881. The reversal of 9999999873 is 3789999999.

It can be written as a sum of positive squares in only one way, i.e., 9371595249 + 628404624 = 96807^2 + 25068^2 .

It is not a de Polignac number, because 9999999873 - 2²⁰ = 9998951297 is a prime.

It is a super-2 number, since 2×9999999873² (a number of 21 digits) contains 22 as substring.

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 9999999792 and 9999999801.

It is not an unprimeable number, because it can be changed into a prime (9999999833) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 555555540 + ... + 555555557.

It is an arithmetic number, because the mean of its divisors is an integer number (2407407379).

Almost surely, 2^9999999873 is an apocalyptic number.

It is an amenable number.

9999999873 is a deficient number, since it is larger than the sum of its proper divisors (4444444401).

9999999873 is a wasteful number, since it uses less digits than its factorization.

9999999873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1111111103 (or 1111111100 counting only the distinct ones).

The product of its digits is 803538792, while the sum is 81.

The square root of 9999999873 is about 99999.9993650000. Note that the first 3 decimals coincide. The cubic root of 9999999873 is about 2154.4346809114.

The spelling of 9999999873 in words is "nine billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, eight hundred seventy-three".