638281 has 4 divisors (see below), whose sum is σ = 729472. Its totient is φ = 547092.

The previous prime is 638269. The next prime is 638303. The reversal of 638281 is 182836.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a de Polignac number, because none of the positive numbers 2^k-638281 is a prime.

It is a super-2 number, since 2×638281² = 814805269922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45585 + ... + 45598.

It is an arithmetic number, because the mean of its divisors is an integer number (182368).

2⁶³⁸²⁸¹ is an apocalyptic number.

It is an amenable number.

638281 is a deficient number, since it is larger than the sum of its proper divisors (91191).

638281 is an equidigital number, since it uses as much as digits as its factorization.

638281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91190.

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

The square root of 638281 is about 798.9249026035. The cubic root of 638281 is about 86.1001627272.

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

The spelling of 638281 in words is "six hundred thirty-eight thousand, two hundred eighty-one".