281604 has 24 divisors (see below), whose sum is σ = 679168. Its totient is φ = 90720.

The previous prime is 281581. The next prime is 281609. The reversal of 281604 is 406182.

It is not an unprimeable number, because it can be changed into a prime (281609) 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, 7 + ... + 750.

2²⁸¹⁶⁰⁴ is an apocalyptic number.

It is an amenable number.

281604 is an abundant number, since it is smaller than the sum of its proper divisors (397564).

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

281604 is a wasteful number, since it uses less digits than its factorization.

281604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 795 (or 793 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 281604 is about 530.6637353353. The cubic root of 281604 is about 65.5460119955.

Adding to 281604 its sum of digits (21), we get a triangular number (281625 = T₇₅₀).

Adding to 281604 its reverse (406182), we get a palindrome (687786).

The spelling of 281604 in words is "two hundred eighty-one thousand, six hundred four".