999440 has 60 divisors (see below), whose sum is σ = 2585772. Its totient is φ = 357120.

The previous prime is 999437. The next prime is 999451. The reversal of 999440 is 44999.

It can be written as a sum of positive squares in 2 ways, for example, as 246016 + 753424 = 496^2 + 868^2 .

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 999440.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 999440.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 32225 + ... + 32255.

2⁹⁹⁹⁴⁴⁰ 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 999440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1292886).

999440 is an abundant number, since it is smaller than the sum of its proper divisors (1586332).

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

999440 is a wasteful number, since it uses less digits than its factorization.

999440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88 (or 51 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 35.

The square root of 999440 is about 999.7199607890. The cubic root of 999440 is about 99.9813298478.

The spelling of 999440 in words is "nine hundred ninety-nine thousand, four hundred forty".