221384 has 8 divisors (see below), whose sum is σ = 415110. Its totient is φ = 110688.

The previous prime is 221327. The next prime is 221393. The reversal of 221384 is 483122.

It can be written as a sum of positive squares in only one way, i.e., 220900 + 484 = 470^2 + 22^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a plaindrome in base 15.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 221384.

It is an unprimeable 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 as a sum of consecutive naturals, namely, 13829 + ... + 13844.

2²²¹³⁸⁴ is an apocalyptic number.

It is an amenable number.

221384 is a deficient number, since it is larger than the sum of its proper divisors (193726).

221384 is a wasteful number, since it uses less digits than its factorization.

221384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27679 (or 27675 counting only the distinct ones).

The product of its digits is 384, while the sum is 20.

The square root of 221384 is about 470.5146118879. The cubic root of 221384 is about 60.4944329281.

The spelling of 221384 in words is "two hundred twenty-one thousand, three hundred eighty-four".