999111988 has 24 divisors (see below), whose sum is σ = 2004172352. Its totient is φ = 426916224.

The previous prime is 999111983. The next prime is 999111991. The reversal of 999111988 is 889111999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999111983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43506 + ... + 62377.

Almost surely, 2^999111988 is an apocalyptic number.

It is an amenable number.

999111988 is an abundant number, since it is smaller than the sum of its proper divisors (1005060364).

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

999111988 is a wasteful number, since it uses less digits than its factorization.

999111988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106231 (or 106229 counting only the distinct ones).

The product of its digits is 419904, while the sum is 55.

The square root of 999111988 is about 31608.7327806731. The cubic root of 999111988 is about 999.7039083384.

The spelling of 999111988 in words is "nine hundred ninety-nine million, one hundred eleven thousand, nine hundred eighty-eight".