20385187 has 4 divisors (see below), whose sum is σ = 20936176. Its totient is φ = 19834200.

The previous prime is 20385181. The next prime is 20385203. The reversal of 20385187 is 78158302.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78158302 = 2 ⋅39079151.

It is a cyclic number.

It is not a de Polignac number, because 20385187 - 2³ = 20385179 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20385181) 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, 275439 + ... + 275512.

It is an arithmetic number, because the mean of its divisors is an integer number (5234044).

Almost surely, 2^20385187 is an apocalyptic number.

20385187 is a deficient number, since it is larger than the sum of its proper divisors (550989).

20385187 is an equidigital number, since it uses as much as digits as its factorization.

20385187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 550988.

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 20385187 is about 4514.9957918031. The cubic root of 20385187 is about 273.1732900423.

It can be divided in two parts, 2038 and 5187, that added together give a square (7225 = 85²).

The spelling of 20385187 in words is "twenty million, three hundred eighty-five thousand, one hundred eighty-seven".