18680645 has 16 divisors (see below), whose sum is σ = 23036400. Its totient is φ = 14536704.

The previous prime is 18680621. The next prime is 18680659. The reversal of 18680645 is 54608681.

It can be written as a sum of positive squares in 8 ways, for example, as 961 + 18679684 = 31^2 + 4322^2 .

It is a cyclic number.

It is not a de Polignac number, because 18680645 - 2¹⁰ = 18679621 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18680599 and 18680608.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 41381 + ... + 41829.

It is an arithmetic number, because the mean of its divisors is an integer number (1439775).

Almost surely, 2^18680645 is an apocalyptic number.

It is an amenable number.

18680645 is a deficient number, since it is larger than the sum of its proper divisors (4355755).

18680645 is a wasteful number, since it uses less digits than its factorization.

18680645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 664.

The product of its (nonzero) digits is 46080, while the sum is 38.

The square root of 18680645 is about 4322.1111739519. Note that the first 4 decimals coincide. The cubic root of 18680645 is about 265.3366789909.

Subtracting 18680645 from its reverse (54608681), we obtain a square (35928036 = 5994²).

The spelling of 18680645 in words is "eighteen million, six hundred eighty thousand, six hundred forty-five".