18516845 has 4 divisors (see below), whose sum is σ = 22220220. Its totient is φ = 14813472.

The previous prime is 18516833. The next prime is 18516851. The reversal of 18516845 is 54861581.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54861581 = 1733 ⋅31657.

It can be written as a sum of positive squares in 2 ways, for example, as 2540836 + 15976009 = 1594^2 + 3997^2 .

It is a cyclic number.

It is not a de Polignac number, because 18516845 - 2⁴ = 18516829 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 18516799 and 18516808.

It is a congruent number.

It is an unprimeable number.

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, 1851680 + ... + 1851689.

It is an arithmetic number, because the mean of its divisors is an integer number (5555055).

Almost surely, 2^18516845 is an apocalyptic number.

It is an amenable number.

18516845 is a deficient number, since it is larger than the sum of its proper divisors (3703375).

18516845 is an equidigital number, since it uses as much as digits as its factorization.

18516845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3703374.

The product of its digits is 38400, while the sum is 38.

The square root of 18516845 is about 4303.1203794456. The cubic root of 18516845 is about 264.5588721194.

The spelling of 18516845 in words is "eighteen million, five hundred sixteen thousand, eight hundred forty-five".