2856209 has 4 divisors (see below), whose sum is σ = 2980416. Its totient is φ = 2732004.

The previous prime is 2856197. The next prime is 2856229. The reversal of 2856209 is 9026582.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2856209 - 2⁸ = 2855953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2856229) 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, 62069 + ... + 62114.

It is an arithmetic number, because the mean of its divisors is an integer number (745104).

2^2856209 is an apocalyptic number.

It is an amenable number.

2856209 is a deficient number, since it is larger than the sum of its proper divisors (124207).

2856209 is a wasteful number, since it uses less digits than its factorization.

2856209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124206.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 2856209 is about 1690.0322482130. The cubic root of 2856209 is about 141.8828796881.

The spelling of 2856209 in words is "two million, eight hundred fifty-six thousand, two hundred nine".