1813209 has 8 divisors (see below), whose sum is σ = 2426592. Its totient is φ = 1204320.

The previous prime is 1813177. The next prime is 1813211. The reversal of 1813209 is 9023181.

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

It is not a de Polignac number, because 1813209 - 2⁵ = 1813177 is a prime.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (1813219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27 + ... + 1904.

It is an arithmetic number, because the mean of its divisors is an integer number (303324).

2^1813209 is an apocalyptic number.

It is an amenable number.

1813209 is a deficient number, since it is larger than the sum of its proper divisors (613383).

1813209 is a wasteful number, since it uses less digits than its factorization.

1813209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2247.

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 1813209 is about 1346.5544920277. The cubic root of 1813209 is about 121.9408698498.

The spelling of 1813209 in words is "one million, eight hundred thirteen thousand, two hundred nine".