900009 has 12 divisors (see below), whose sum is σ = 1418352.
Its totient is φ = 545400.
The previous prime is 900007. The next prime is 900019.
900009 is nontrivially palindromic in base 10.
It is not a de Polignac number, because 900009 - 21 = 900007 is a prime.
It is an Ulam number.
It is a nialpdrome in base 16.
It is a junction number, because it is equal to n+sod(n) for n = 899964 and 900000.
It is not an unprimeable number, because it can be changed into a prime (900001) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (13) of ones.
It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4447 + ... + 4644.
It is an arithmetic number, because the mean of its divisors is an integer number (118196).
2900009 is an apocalyptic number.
900009 is a gapful number since it is divisible by the number (99) formed by its first and last digit.
It is an amenable number.
900009 is a deficient number, since it is larger than the sum of its proper divisors (518343).
900009 is a wasteful number, since it uses less digits than its factorization.
900009 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 9108 (or 9105 counting only the distinct ones).
The product of its (nonzero) digits is 81, while the sum is 18.
The square root of 900009 is about 948.6880414551.
The cubic root of 900009 is about 96.5492602893.
It can be divided in two parts, 90000 and 9, that multiplied together give a 4-th power (810000 = 304).
The spelling of 900009 in words is "nine hundred thousand, nine".