9999999855 has 32 divisors (see below), whose sum is σ = 17905708800. Its totient is φ = 5294954016.

The previous prime is 9999999851. The next prime is 9999999881. The reversal of 9999999855 is 5589999999.

It is not a de Polignac number, because 9999999855 - 2² = 9999999851 is a prime.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9999999851) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 247689 + ... + 285218.

It is an arithmetic number, because the mean of its divisors is an integer number (559553400).

Almost surely, 2^9999999855 is an apocalyptic number.

9999999855 is a deficient number, since it is larger than the sum of its proper divisors (7905708945).

9999999855 is a wasteful number, since it uses less digits than its factorization.

9999999855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 533060 (or 533054 counting only the distinct ones).

The product of its digits is 956593800, while the sum is 81.

The square root of 9999999855 is about 99999.9992750000. Note that the first 3 decimals coincide. The cubic root of 9999999855 is about 2154.4346796188.

The spelling of 9999999855 in words is "nine billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, eight hundred fifty-five".