221617 has 4 divisors (see below), whose sum is σ = 241776. Its totient is φ = 201460.

The previous prime is 221603. The next prime is 221621. The reversal of 221617 is 716122.

221617 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 221617 - 2⁷ = 221489 is a prime.

It is a super-2 number, since 2×221617² = 98228189378, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221594 and 221603.

It is not an unprimeable number, because it can be changed into a prime (221657) 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, 10063 + ... + 10084.

It is an arithmetic number, because the mean of its divisors is an integer number (60444).

2²²¹⁶¹⁷ is an apocalyptic number.

It is an amenable number.

221617 is a deficient number, since it is larger than the sum of its proper divisors (20159).

221617 is a wasteful number, since it uses less digits than its factorization.

221617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20158.

The product of its digits is 168, while the sum is 19.

The square root of 221617 is about 470.7621480111. The cubic root of 221617 is about 60.5156483439.

Adding to 221617 its reverse (716122), we get a palindrome (937739).

It can be divided in two parts, 221 and 617, that added together give a palindrome (838).

The spelling of 221617 in words is "two hundred twenty-one thousand, six hundred seventeen".