221839 has 4 divisors (see below), whose sum is σ = 224224. Its totient is φ = 219456.

The previous prime is 221831. The next prime is 221849. The reversal of 221839 is 938122.

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 221839 - 2³ = 221831 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221831) 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, 1047 + ... + 1240.

It is an arithmetic number, because the mean of its divisors is an integer number (56056).

2²²¹⁸³⁹ is an apocalyptic number.

221839 is a deficient number, since it is larger than the sum of its proper divisors (2385).

221839 is an equidigital number, since it uses as much as digits as its factorization.

221839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2384.

The product of its digits is 864, while the sum is 25.

The square root of 221839 is about 470.9978768530. The cubic root of 221839 is about 60.5358483444.

The spelling of 221839 in words is "two hundred twenty-one thousand, eight hundred thirty-nine".