9999555111 has 128 divisors (see below), whose sum is σ = 18642032640. Its totient is φ = 5157540864.

The previous prime is 9999555107. The next prime is 9999555119. The reversal of 9999555111 is 1115559999.

It is not a de Polignac number, because 9999555111 - 2² = 9999555107 is a prime.

It is a super-2 number, since 2×9999555111² (a number of 21 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9999555119) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 35333976 + ... + 35334258.

It is an arithmetic number, because the mean of its divisors is an integer number (145640880).

Almost surely, 2^9999555111 is an apocalyptic number.

9999555111 is a gapful number since it is divisible by the number (91) formed by its first and last digit.

9999555111 is a deficient number, since it is larger than the sum of its proper divisors (8642477529).

9999555111 is a wasteful number, since it uses less digits than its factorization.

9999555111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 582 (or 576 counting only the distinct ones).

The product of its digits is 820125, while the sum is 54.

The square root of 9999555111 is about 99997.7755302587. The cubic root of 9999555111 is about 2154.4027400816.

The spelling of 9999555111 in words is "nine billion, nine hundred ninety-nine million, five hundred fifty-five thousand, one hundred eleven".