2100009 has 8 divisors (see below), whose sum is σ = 2875840. Its totient is φ = 1362096.

The previous prime is 2100001. The next prime is 2100011. The reversal of 2100009 is 9000012.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2100009 - 2³ = 2100001 is a prime.

It is a Duffinian number.

It is a Curzon number.

2100009 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 2099967 and 2100003.

It is not an unprimeable number, because it can be changed into a prime (2100001) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 9349 + ... + 9570.

It is an arithmetic number, because the mean of its divisors is an integer number (359480).

2^2100009 is an apocalyptic number.

It is an amenable number.

2100009 is a deficient number, since it is larger than the sum of its proper divisors (775831).

2100009 is a wasteful number, since it uses less digits than its factorization.

2100009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18959.

The product of its (nonzero) digits is 18, while the sum is 12.

The square root of 2100009 is about 1449.1407799106. The cubic root of 2100009 is about 128.0580994384.

The spelling of 2100009 in words is "two million, one hundred thousand, nine".