20285317 has 4 divisors (see below), whose sum is σ = 21845740. Its totient is φ = 18724896.

The previous prime is 20285303. The next prime is 20285327. The reversal of 20285317 is 71358202.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 71358202 = 2 ⋅35679101.

It can be written as a sum of positive squares in 2 ways, for example, as 8444836 + 11840481 = 2906^2 + 3441^2 .

It is a cyclic number.

It is not a de Polignac number, because 20285317 - 2¹⁹ = 19761029 is a prime.

It is a super-2 number, since 2×20285317² = 822988171580978, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20285327) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 780192 + ... + 780217.

It is an arithmetic number, because the mean of its divisors is an integer number (5461435).

Almost surely, 2^20285317 is an apocalyptic number.

It is an amenable number.

20285317 is a deficient number, since it is larger than the sum of its proper divisors (1560423).

20285317 is a wasteful number, since it uses less digits than its factorization.

20285317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1560422.

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 20285317 is about 4503.9224016406. The cubic root of 20285317 is about 272.7264542972.

It can be divided in two parts, 20285 and 317, that added together give a palindrome (20602).

The spelling of 20285317 in words is "twenty million, two hundred eighty-five thousand, three hundred seventeen".