221771 has 4 divisors (see below), whose sum is σ = 241944. Its totient is φ = 201600.

The previous prime is 221747. The next prime is 221773. The reversal of 221771 is 177122.

221771 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.

It is a cyclic number.

It is not a de Polignac number, because 221771 - 2⁶ = 221707 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 221771.

It is not an unprimeable number, because it can be changed into a prime (221773) 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, 10070 + ... + 10091.

It is an arithmetic number, because the mean of its divisors is an integer number (60486).

2²²¹⁷⁷¹ is an apocalyptic number.

221771 is a deficient number, since it is larger than the sum of its proper divisors (20173).

221771 is a wasteful number, since it uses less digits than its factorization.

221771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20172.

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

The square root of 221771 is about 470.9256841583. The cubic root of 221771 is about 60.5296623892.

Adding to 221771 its reverse (177122), we get a palindrome (398893).

The spelling of 221771 in words is "two hundred twenty-one thousand, seven hundred seventy-one", and thus it is an iban number.