1806541 has 4 divisors (see below), whose sum is σ = 1970784. Its totient is φ = 1642300.

The previous prime is 1806533. The next prime is 1806551. The reversal of 1806541 is 1456081.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1456081 = 11 ⋅132371.

It is not a de Polignac number, because 1806541 - 2³ = 1806533 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1806551) 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, 82105 + ... + 82126.

It is an arithmetic number, because the mean of its divisors is an integer number (492696).

2^1806541 is an apocalyptic number.

1806541 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1806541 is a deficient number, since it is larger than the sum of its proper divisors (164243).

1806541 is a wasteful number, since it uses less digits than its factorization.

1806541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164242.

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 1806541 is about 1344.0762627173. The cubic root of 1806541 is about 121.7912087651.

The spelling of 1806541 in words is "one million, eight hundred six thousand, five hundred forty-one".