638216481 has 8 divisors (see below), whose sum is σ = 972520384. Its totient is φ = 364695120.

The previous prime is 638216471. The next prime is 638216507. The reversal of 638216481 is 184612836.

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

It is not a de Polignac number, because 638216481 - 2⁷ = 638216353 is a prime.

It is a super-2 number, since 2×638216481² = 814640553240046722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638216471) 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 7 ways as a sum of consecutive naturals, for example, 15195610 + ... + 15195651.

It is an arithmetic number, because the mean of its divisors is an integer number (121565048).

Almost surely, 2^638216481 is an apocalyptic number.

It is an amenable number.

638216481 is a deficient number, since it is larger than the sum of its proper divisors (334303903).

638216481 is a wasteful number, since it uses less digits than its factorization.

638216481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30391271.

The product of its digits is 55296, while the sum is 39.

The square root of 638216481 is about 25262.9467996115. The cubic root of 638216481 is about 860.9726155799.

The spelling of 638216481 in words is "six hundred thirty-eight million, two hundred sixteen thousand, four hundred eighty-one".