1816985 has 4 divisors (see below), whose sum is σ = 2180388. Its totient is φ = 1453584.

The previous prime is 1816979. The next prime is 1816987. The reversal of 1816985 is 5896181.

1816985 is an esthetic number in base 4, because in such base its adjacent digits differ by 1.

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 350464 + 1466521 = 592^2 + 1211^2 .

It is a cyclic number.

It is not a de Polignac number, because 1816985 - 2⁸ = 1816729 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1816987) 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 3 ways as a sum of consecutive naturals, for example, 181694 + ... + 181703.

It is an arithmetic number, because the mean of its divisors is an integer number (545097).

2^1816985 is an apocalyptic number.

It is an amenable number.

1816985 is a deficient number, since it is larger than the sum of its proper divisors (363403).

1816985 is an equidigital number, since it uses as much as digits as its factorization.

1816985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 363402.

The product of its digits is 17280, while the sum is 38.

The square root of 1816985 is about 1347.9558598114. The cubic root of 1816985 is about 122.0254582722.

The spelling of 1816985 in words is "one million, eight hundred sixteen thousand, nine hundred eighty-five".