18680985 has 12 divisors (see below), whose sum is σ = 32380452. Its totient is φ = 9963168.

The previous prime is 18680929. The next prime is 18680989. The reversal of 18680985 is 58908681.

It can be written as a sum of positive squares in 2 ways, for example, as 4460544 + 14220441 = 2112^2 + 3771^2 .

It is not a de Polignac number, because 18680985 - 2⁸ = 18680729 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 415133 = 18680985 / (1 + 8 + 6 + 8 + 0 + 9 + 8 + 5).

It is a self number, because there is not a number n which added to its sum of digits gives 18680985.

It is not an unprimeable number, because it can be changed into a prime (18680989) 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 11 ways as a sum of consecutive naturals, for example, 207522 + ... + 207611.

It is an arithmetic number, because the mean of its divisors is an integer number (2698371).

Almost surely, 2^18680985 is an apocalyptic number.

18680985 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18680985 is a deficient number, since it is larger than the sum of its proper divisors (13699467).

18680985 is a wasteful number, since it uses less digits than its factorization.

18680985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 415144 (or 415141 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 45.

The square root of 18680985 is about 4322.1505064030. The cubic root of 18680985 is about 265.3382887484.

The spelling of 18680985 in words is "eighteen million, six hundred eighty thousand, nine hundred eighty-five".