281603 has 8 divisors (see below), whose sum is σ = 328800. Its totient is φ = 241080.

The previous prime is 281581. The next prime is 281609. The reversal of 281603 is 306182.

It is not a de Polignac number, because 281603 - 2⁶ = 281539 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (281609) 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, 68 + ... + 753.

It is an arithmetic number, because the mean of its divisors is an integer number (41100).

2²⁸¹⁶⁰³ is an apocalyptic number.

281603 is a deficient number, since it is larger than the sum of its proper divisors (47197).

281603 is an frugal number, since it uses more digits than its factorization.

281603 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 842 (or 828 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 281603 is about 530.6627931182. The cubic root of 281603 is about 65.5459344089.

Adding to 281603 its reverse (306182), we get a palindrome (587785).

The spelling of 281603 in words is "two hundred eighty-one thousand, six hundred three".