281638 has 8 divisors (see below), whose sum is σ = 482832. Its totient is φ = 120696.

The previous prime is 281627. The next prime is 281641. The reversal of 281638 is 836182.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10045 + ... + 10072.

It is an arithmetic number, because the mean of its divisors is an integer number (60354).

2²⁸¹⁶³⁸ is an apocalyptic number.

281638 is a deficient number, since it is larger than the sum of its proper divisors (201194).

281638 is a wasteful number, since it uses less digits than its factorization.

281638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20126.

The product of its digits is 2304, while the sum is 28.

The square root of 281638 is about 530.6957697212. The cubic root of 281638 is about 65.5486498306.

It can be divided in two parts, 281 and 638, that added together give a palindrome (919).

The spelling of 281638 in words is "two hundred eighty-one thousand, six hundred thirty-eight".