1806521 has 8 divisors (see below), whose sum is σ = 1868640. Its totient is φ = 1745568.

The previous prime is 1806509. The next prime is 1806527. The reversal of 1806521 is 1256081.

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

It is a cyclic number.

It is not a de Polignac number, because 1806521 - 2¹⁰ = 1805497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1806527) 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 7 ways as a sum of consecutive naturals, for example, 3725 + ... + 4181.

It is an arithmetic number, because the mean of its divisors is an integer number (233580).

2^1806521 is an apocalyptic number.

It is an amenable number.

1806521 is a deficient number, since it is larger than the sum of its proper divisors (62119).

1806521 is an equidigital number, since it uses as much as digits as its factorization.

1806521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 583.

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

The square root of 1806521 is about 1344.0688226427. The cubic root of 1806521 is about 121.7907593181.

The spelling of 1806521 in words is "one million, eight hundred six thousand, five hundred twenty-one".