18820685 has 12 divisors (see below), whose sum is σ = 24456852. Its totient is φ = 13897728.

The previous prime is 18820673. The next prime is 18820687. The reversal of 18820685 is 58602881.

It can be written as a sum of positive squares in 6 ways, for example, as 10259209 + 8561476 = 3203^2 + 2926^2 .

It is not a de Polignac number, because 18820685 - 2⁸ = 18820429 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18820687) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10292 + ... + 11981.

It is an arithmetic number, because the mean of its divisors is an integer number (2038071).

Almost surely, 2^18820685 is an apocalyptic number.

It is an amenable number.

18820685 is a deficient number, since it is larger than the sum of its proper divisors (5636167).

18820685 is a wasteful number, since it uses less digits than its factorization.

18820685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22304 (or 22291 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 38.

The square root of 18820685 is about 4338.2813417297. The cubic root of 18820685 is about 265.9980637543.

It can be divided in two parts, 18 and 820685, that multiplied together give a triangular number (14772330 = T₅₄₃₅).

The spelling of 18820685 in words is "eighteen million, eight hundred twenty thousand, six hundred eighty-five".