999869988 has 48 divisors (see below), whose sum is σ = 2520544320. Its totient is φ = 306666624.

The previous prime is 999869957. The next prime is 999869989. The reversal of 999869988 is 889968999.

999869988 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (999869989) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39343 + ... + 59561.

It is an arithmetic number, because the mean of its divisors is an integer number (52511340).

Almost surely, 2^999869988 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 999869988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1260272160).

999869988 is an abundant number, since it is smaller than the sum of its proper divisors (1520674332).

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

999869988 is a wasteful number, since it uses less digits than its factorization.

999869988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20556 (or 20554 counting only the distinct ones).

The product of its digits is 181398528, while the sum is 75.

The square root of 999869988 is about 31620.7208646482. The cubic root of 999869988 is about 999.9566607884.

The spelling of 999869988 in words is "nine hundred ninety-nine million, eight hundred sixty-nine thousand, nine hundred eighty-eight".