20170217 has 4 divisors (see below), whose sum is σ = 20715396. Its totient is φ = 19625040.

The previous prime is 20170193. The next prime is 20170219. The reversal of 20170217 is 71207102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 71207102 = 2 ⋅35603551.

It can be written as a sum of positive squares in 2 ways, for example, as 14318656 + 5851561 = 3784^2 + 2419^2 .

It is a cyclic number.

It is not a de Polignac number, because 20170217 - 2¹² = 20166121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20170219) 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, 272534 + ... + 272607.

It is an arithmetic number, because the mean of its divisors is an integer number (5178849).

Almost surely, 2^20170217 is an apocalyptic number.

It is an amenable number.

20170217 is a deficient number, since it is larger than the sum of its proper divisors (545179).

20170217 is an equidigital number, since it uses as much as digits as its factorization.

20170217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 545178.

The product of its (nonzero) digits is 196, while the sum is 20.

The square root of 20170217 is about 4491.1264733917. The cubic root of 20170217 is about 272.2096539958.

Adding to 20170217 its reverse (71207102), we get a palindrome (91377319).

The spelling of 20170217 in words is "twenty million, one hundred seventy thousand, two hundred seventeen".