20285217 has 24 divisors (see below), whose sum is σ = 31023200. Its totient is φ = 12737088.

The previous prime is 20285099. The next prime is 20285263. The reversal of 20285217 is 71258202.

It is not a de Polignac number, because 20285217 - 2¹⁰ = 20284193 is a prime.

It is a super-2 number, since 2×20285217² = 822980057474178, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20285017) 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 23 ways as a sum of consecutive naturals, for example, 53334 + ... + 53712.

Almost surely, 2^20285217 is an apocalyptic number.

It is an amenable number.

20285217 is a deficient number, since it is larger than the sum of its proper divisors (10737983).

20285217 is a wasteful number, since it uses less digits than its factorization.

20285217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 717 (or 714 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 20285217 is about 4503.9113001923. The cubic root of 20285217 is about 272.7260061456.

It can be divided in two parts, 20285 and 217, that added together give a palindrome (20502).

The spelling of 20285217 in words is "twenty million, two hundred eighty-five thousand, two hundred seventeen".