2509209 has 6 divisors (see below), whose sum is σ = 3624426. Its totient is φ = 1672800.

The previous prime is 2509207. The next prime is 2509219. The reversal of 2509209 is 9029052.

It can be written as a sum of positive squares in only one way, i.e., 2471184 + 38025 = 1572^2 + 195^2 .

It is not a de Polignac number, because 2509209 - 2¹ = 2509207 is a prime.

It is a super-2 number, since 2×2509209² = 12592259611362, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2509207) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 139392 + ... + 139409.

It is an arithmetic number, because the mean of its divisors is an integer number (604071).

2^2509209 is an apocalyptic number.

It is an amenable number.

2509209 is a deficient number, since it is larger than the sum of its proper divisors (1115217).

2509209 is a wasteful number, since it uses less digits than its factorization.

2509209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278807 (or 278804 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

The square root of 2509209 is about 1584.0482947183. The cubic root of 2509209 is about 135.8873237725.

The spelling of 2509209 in words is "two million, five hundred nine thousand, two hundred nine".