19221 has 8 divisors (see below), whose sum is σ = 26400. Its totient is φ = 12432.

The previous prime is 19219. The next prime is 19231. The reversal of 19221 is 12291.

It is a happy number.

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

It is not a de Polignac number, because 19221 - 2¹ = 19219 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19211) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 55 + ... + 203.

It is an arithmetic number, because the mean of its divisors is an integer number (3300).

2¹⁹²²¹ is an apocalyptic number.

It is an amenable number.

19221 is a deficient number, since it is larger than the sum of its proper divisors (7179).

19221 is a wasteful number, since it uses less digits than its factorization.

19221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195.

The product of its digits is 36, while the sum is 15.

The square root of 19221 is about 138.6398211193. The cubic root of 19221 is about 26.7870770100.

The spelling of 19221 in words is "nineteen thousand, two hundred twenty-one".