221016 has 16 divisors (see below), whose sum is σ = 552600. Its totient is φ = 73664.

The previous prime is 220973. The next prime is 221021. The reversal of 221016 is 610122.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 220992 and 221010.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 221016.

It is an unprimeable number.

221016 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 3 ways as a sum of consecutive naturals, for example, 4581 + ... + 4628.

2²²¹⁰¹⁶ is an apocalyptic number.

It is an amenable number.

221016 is an abundant number, since it is smaller than the sum of its proper divisors (331584).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221016 is a wasteful number, since it uses less digits than its factorization.

221016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9218 (or 9214 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 221016 is about 470.1233880589. The cubic root of 221016 is about 60.4608949762.

Adding to 221016 its reverse (610122), we get a palindrome (831138).

The spelling of 221016 in words is "two hundred twenty-one thousand, sixteen".