281216 has 32 divisors (see below), whose sum is σ = 606900. Its totient is φ = 129792.

The previous prime is 281207. The next prime is 281227. The reversal of 281216 is 612182.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 2 ways, for example, as 87616 + 193600 = 296^2 + 440^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 281216.

It is an unprimeable number.

281216 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 (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21626 + ... + 21638.

2²⁸¹²¹⁶ is an apocalyptic number.

281216 is a gapful number since it is divisible by the number (26) 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 281216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (303450).

281216 is an abundant number, since it is smaller than the sum of its proper divisors (325684).

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

281216 is an frugal number, since it uses more digits than its factorization.

281216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53 (or 15 counting only the distinct ones).

The product of its digits is 192, while the sum is 20.

The square root of 281216 is about 530.2980294136. The cubic root of 281216 is about 65.5158945945.

Adding to 281216 its reverse (612182), we get a palindrome (893398).

It can be divided in two parts, 2 and 81216, that added together give a palindrome (81218).

The spelling of 281216 in words is "two hundred eighty-one thousand, two hundred sixteen".