638481 has 4 divisors (see below), whose sum is σ = 851312. Its totient is φ = 425652.

The previous prime is 638467. The next prime is 638489. The reversal of 638481 is 184836.

It is a happy number.

638481 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 not a de Polignac number, because 638481 - 2¹⁹ = 114193 is a prime.

It is a super-2 number, since 2×638481² = 815315974722, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638489) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106411 + ... + 106416.

It is an arithmetic number, because the mean of its divisors is an integer number (212828).

2⁶³⁸⁴⁸¹ is an apocalyptic number.

It is an amenable number.

638481 is a deficient number, since it is larger than the sum of its proper divisors (212831).

638481 is a wasteful number, since it uses less digits than its factorization.

638481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212830.

The product of its digits is 4608, while the sum is 30.

The square root of 638481 is about 799.0500610099. The cubic root of 638481 is about 86.1091547095.

The spelling of 638481 in words is "six hundred thirty-eight thousand, four hundred eighty-one".