221291 has 8 divisors (see below), whose sum is σ = 256224. Its totient is φ = 187200.

The previous prime is 221281. The next prime is 221303. The reversal of 221291 is 192122.

221291 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 221291 - 2⁶ = 221227 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 551 + ... + 863.

It is an arithmetic number, because the mean of its divisors is an integer number (32028).

2²²¹²⁹¹ is an apocalyptic number.

221291 is a deficient number, since it is larger than the sum of its proper divisors (34933).

221291 is a wasteful number, since it uses less digits than its factorization.

221291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 421.

The product of its digits is 72, while the sum is 17.

The square root of 221291 is about 470.4157735451. The cubic root of 221291 is about 60.4859608159.

It can be divided in two parts, 221 and 291, that added together give a 9-th power (512 = 2⁹).

The spelling of 221291 in words is "two hundred twenty-one thousand, two hundred ninety-one".