221984 has 24 divisors (see below), whose sum is σ = 499968. Its totient is φ = 95040.

The previous prime is 221957. The next prime is 221987. The reversal of 221984 is 489122.

It is not an unprimeable number, because it can be changed into a prime (221987) by changing a digit.

221984 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 (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 272 + ... + 719.

It is an arithmetic number, because the mean of its divisors is an integer number (20832).

2²²¹⁹⁸⁴ is an apocalyptic number.

It is an amenable number.

221984 is an abundant number, since it is smaller than the sum of its proper divisors (277984).

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

221984 is an equidigital number, since it uses as much as digits as its factorization.

221984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1008 (or 1000 counting only the distinct ones).

The product of its digits is 1152, while the sum is 26.

The square root of 221984 is about 471.1517802153. The cubic root of 221984 is about 60.5490347637.

The spelling of 221984 in words is "two hundred twenty-one thousand, nine hundred eighty-four".