20216617 has 4 divisors (see below), whose sum is σ = 20443860. Its totient is φ = 19989376.

The previous prime is 20216593. The next prime is 20216633. The reversal of 20216617 is 71661202.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4064256 + 16152361 = 2016^2 + 4019^2 .

It is a cyclic number.

It is not a de Polignac number, because 20216617 - 2⁷ = 20216489 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20216591 and 20216600.

It is not an unprimeable number, because it can be changed into a prime (20216017) 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, 113488 + ... + 113665.

It is an arithmetic number, because the mean of its divisors is an integer number (5110965).

Almost surely, 2^20216617 is an apocalyptic number.

It is an amenable number.

20216617 is a deficient number, since it is larger than the sum of its proper divisors (227243).

20216617 is an equidigital number, since it uses as much as digits as its factorization.

20216617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227242.

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 20216617 is about 4496.2892478131. The cubic root of 20216617 is about 272.4182264523.

Adding to 20216617 its reverse (71661202), we get a palindrome (91877819).

The spelling of 20216617 in words is "twenty million, two hundred sixteen thousand, six hundred seventeen".