999931440 has 160 divisors (see below), whose sum is σ = 3276933120. Its totient is φ = 251716608.

The previous prime is 999931433. The next prime is 999931441. The reversal of 999931440 is 44139999.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 999931440.

It is not an unprimeable number, because it can be changed into a prime (999931441) 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 31 ways as a sum of consecutive naturals, for example, 434934 + ... + 437226.

It is an arithmetic number, because the mean of its divisors is an integer number (20480832).

Almost surely, 2^999931440 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 999931440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1638466560).

999931440 is an abundant number, since it is smaller than the sum of its proper divisors (2277001680).

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

999931440 is a wasteful number, since it uses less digits than its factorization.

999931440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2411 (or 2405 counting only the distinct ones).

The product of its (nonzero) digits is 314928, while the sum is 48.

The square root of 999931440 is about 31621.6925543210. The cubic root of 999931440 is about 999.9771461444.

The spelling of 999931440 in words is "nine hundred ninety-nine million, nine hundred thirty-one thousand, four hundred forty".