999944 has 24 divisors (see below), whose sum is σ = 2062830. Its totient is φ = 454080.

The previous prime is 999931. The next prime is 999953. The reversal of 999944 is 449999.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 592900 + 407044 = 770^2 + 638^2 .

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 999895 and 999904.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 452 + ... + 1484.

2⁹⁹⁹⁹⁴⁴ 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 999944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1031415).

999944 is an abundant number, since it is smaller than the sum of its proper divisors (1062886).

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

999944 is a wasteful number, since it uses less digits than its factorization.

999944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1061 (or 1046 counting only the distinct ones).

The product of its digits is 104976, while the sum is 44.

The square root of 999944 is about 999.9719996080. The cubic root of 999944 is about 99.9981332985.

Subtracting from 999944 its reverse (449999), we obtain a palindrome (549945).

The spelling of 999944 in words is "nine hundred ninety-nine thousand, nine hundred forty-four".