999444999 has 16 divisors (see below), whose sum is σ = 1564126208. Its totient is φ = 555675552.

The previous prime is 999444997. The next prime is 999445039.

999444999 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 999444999 - 2¹ = 999444997 is a prime.

It is a super-2 number, since 2×999444999² = 1997780612052220002, which contains 22 as substring.

It is a Duffinian number.

It is a zygodrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999444997) 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, 642367 + ... + 643920.

It is an arithmetic number, because the mean of its divisors is an integer number (97757888).

Almost surely, 2^999444999 is an apocalyptic number.

999444999 is a deficient number, since it is larger than the sum of its proper divisors (564681209).

999444999 is a wasteful number, since it uses less digits than its factorization.

999444999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1286334.

The product of its digits is 34012224, while the sum is 66.

The square root of 999444999 is about 31614.0000474473. Note that the first 4 decimals coincide. The cubic root of 999444999 is about 999.8149654310.

The spelling of 999444999 in words is "nine hundred ninety-nine million, four hundred forty-four thousand, nine hundred ninety-nine".