281664 has 56 divisors (see below), whose sum is σ = 833120. Its totient is φ = 93312.

The previous prime is 281663. The next prime is 281669. The reversal of 281664 is 466182.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nude number because it is divisible by every one of its digits.

It is an Ulam number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 281664.

It is not an unprimeable number, because it can be changed into a prime (281663) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 1647 + ... + 1809.

281664 is a Friedman number, since it can be written as (8+6^4)*6^(2+1), using all its digits and the basic arithmetic operations.

2²⁸¹⁶⁶⁴ is an apocalyptic number.

281664 is a gapful number since it is divisible by the number (24) 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 281664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (416560).

281664 is an abundant number, since it is smaller than the sum of its proper divisors (551456).

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

281664 is a wasteful number, since it uses less digits than its factorization.

281664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184 (or 168 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 281664 is about 530.7202652999. The cubic root of 281664 is about 65.5506668554.

The spelling of 281664 in words is "two hundred eighty-one thousand, six hundred sixty-four".