221280 has 48 divisors (see below), whose sum is σ = 698544. Its totient is φ = 58880.

The previous prime is 221261. The next prime is 221281. The reversal of 221280 is 82122.

221280 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221281) 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, 250 + ... + 710.

It is an arithmetic number, because the mean of its divisors is an integer number (14553).

2²²¹²⁸⁰ is an apocalyptic number.

221280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (349272).

221280 is an abundant number, since it is smaller than the sum of its proper divisors (477264).

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

221280 is a wasteful number, since it uses less digits than its factorization.

221280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 479 (or 471 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 221280 is about 470.4040816149. The cubic root of 221280 is about 60.4849585812.

The spelling of 221280 in words is "two hundred twenty-one thousand, two hundred eighty".