1806005 has 6 divisors (see below), whose sum is σ = 2170818. Its totient is φ = 1442400.

The previous prime is 1806001. The next prime is 1806011. The reversal of 1806005 is 5006081.

It can be written as a sum of positive squares in 3 ways, for example, as 743044 + 1062961 = 862^2 + 1031^2 .

It is not a de Polignac number, because 1806005 - 2² = 1806001 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1806001) 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 5 ways as a sum of consecutive naturals, for example, 2705 + ... + 3305.

It is an arithmetic number, because the mean of its divisors is an integer number (361803).

2^1806005 is an apocalyptic number.

It is an amenable number.

1806005 is a deficient number, since it is larger than the sum of its proper divisors (364813).

1806005 is an frugal number, since it uses more digits than its factorization.

1806005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1207 (or 606 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 1806005 is about 1343.8768544774. The cubic root of 1806005 is about 121.7791624391.

Multiplying 1806005 by its sum of digits (20), we get a square (36120100 = 6010²).

The spelling of 1806005 in words is "one million, eight hundred six thousand, five".