2218809 has 4 divisors (see below), whose sum is σ = 2958416. Its totient is φ = 1479204.

The previous prime is 2218807. The next prime is 2218831. The reversal of 2218809 is 9088122.

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 not a de Polignac number, because 2218809 - 2¹ = 2218807 is a prime.

It is a super-2 number, since 2×2218809² = 9846226756962, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2218807) 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, 369799 + ... + 369804.

It is an arithmetic number, because the mean of its divisors is an integer number (739604).

2^2218809 is an apocalyptic number.

It is an amenable number.

2218809 is a deficient number, since it is larger than the sum of its proper divisors (739607).

2218809 is an equidigital number, since it uses as much as digits as its factorization.

2218809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 739606.

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 2218809 is about 1489.5667155250. The cubic root of 2218809 is about 130.4287422372.

The spelling of 2218809 in words is "two million, two hundred eighteen thousand, eight hundred nine".