1806663 has 4 divisors (see below), whose sum is σ = 2408888. Its totient is φ = 1204440.

The previous prime is 1806643. The next prime is 1806683. The reversal of 1806663 is 3666081.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3666081 = 3 ⋅1222027.

It is an interprime number because it is at equal distance from previous prime (1806643) and next prime (1806683).

It is not a de Polignac number, because 1806663 - 2⁵ = 1806631 is a prime.

It is a D-number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1806663.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1806643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 301108 + ... + 301113.

It is an arithmetic number, because the mean of its divisors is an integer number (602222).

2^1806663 is an apocalyptic number.

1806663 is a deficient number, since it is larger than the sum of its proper divisors (602225).

1806663 is an equidigital number, since it uses as much as digits as its factorization.

1806663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 602224.

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 1806663 is about 1344.1216462806. The cubic root of 1806663 is about 121.7939503198.

It can be divided in two parts, 1806 and 663, that multiplied together give a triangular number (1197378 = T₁₅₄₇).

The spelling of 1806663 in words is "one million, eight hundred six thousand, six hundred sixty-three".