2090909 has 4 divisors (see below), whose sum is σ = 2093916. Its totient is φ = 2087904.

The previous prime is 2090873. The next prime is 2090923. The reversal of 2090909 is 9090902.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 9090902 = 2 ⋅4545451.

It can be written as a sum of positive squares in 2 ways, for example, as 1968409 + 122500 = 1403^2 + 350^2 .

It is a cyclic number.

It is not a de Polignac number, because 2090909 - 2²⁰ = 1042333 is a prime.

It is a Duffinian number.

2090909 is a modest number, since divided by 909 gives 209 as remainder.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2090989) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 137 + ... + 2049.

It is an arithmetic number, because the mean of its divisors is an integer number (523479).

2^2090909 is an apocalyptic number.

It is an amenable number.

2090909 is a deficient number, since it is larger than the sum of its proper divisors (3007).

2090909 is a wasteful number, since it uses less digits than its factorization.

2090909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3006.

The product of its (nonzero) digits is 1458, while the sum is 29.

The square root of 2090909 is about 1445.9975795277. The cubic root of 2090909 is about 127.8728595951.

The spelling of 2090909 in words is "two million, ninety thousand, nine hundred nine".