999001900 has 72 divisors (see below), whose sum is σ = 2391659424. Its totient is φ = 359846400.

The previous prime is 999001897. The next prime is 999001901. The reversal of 999001900 is 9100999.

It is a super-2 number, since 2×999001900² = 1996009592407220000, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 999001900.

It is not an unprimeable number, because it can be changed into a prime (999001901) 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 23 ways as a sum of consecutive naturals, for example, 43929 + ... + 62671.

It is an arithmetic number, because the mean of its divisors is an integer number (33217492).

Almost surely, 2^999001900 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 999001900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1195829712).

999001900 is an abundant number, since it is smaller than the sum of its proper divisors (1392657524).

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

999001900 is a wasteful number, since it uses less digits than its factorization.

999001900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18811 (or 18804 counting only the distinct ones).

The product of its (nonzero) digits is 6561, while the sum is 37.

The square root of 999001900 is about 31606.9913152138. The cubic root of 999001900 is about 999.6671892493.

The spelling of 999001900 in words is "nine hundred ninety-nine million, one thousand, nine hundred".