1812605 has 4 divisors (see below), whose sum is σ = 2175132. Its totient is φ = 1450080.

The previous prime is 1812589. The next prime is 1812611. The reversal of 1812605 is 5062181.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 219961 + 1592644 = 469^2 + 1262^2 .

It is not a de Polignac number, because 1812605 - 2⁴ = 1812589 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 181256 + ... + 181265.

It is an arithmetic number, because the mean of its divisors is an integer number (543783).

2^1812605 is an apocalyptic number.

It is an amenable number.

1812605 is a deficient number, since it is larger than the sum of its proper divisors (362527).

1812605 is an equidigital number, since it uses as much as digits as its factorization.

1812605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 362526.

The product of its (nonzero) digits is 480, while the sum is 23.

The square root of 1812605 is about 1346.3301972399. The cubic root of 1812605 is about 121.9273283947.

Adding to 1812605 its reverse (5062181), we get a palindrome (6874786).

The spelling of 1812605 in words is "one million, eight hundred twelve thousand, six hundred five".