638421541152 has 96 divisors (see below), whose sum is σ = 1686172723200. Its totient is φ = 211499608320.

The previous prime is 638421541123. The next prime is 638421541159. The reversal of 638421541152 is 251145124836.

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (638421541159) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17385403 + ... + 17422085.

It is an arithmetic number, because the mean of its divisors is an integer number (17564299200).

Almost surely, 2^638421541152 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638421541152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (843086361600).

638421541152 is an abundant number, since it is smaller than the sum of its proper divisors (1047751182048).

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

638421541152 is a wasteful number, since it uses less digits than its factorization.

638421541152 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37806 (or 37798 counting only the distinct ones).

The product of its digits is 230400, while the sum is 42.

Adding to 638421541152 its reverse (251145124836), we get a palindrome (889566665988).

The spelling of 638421541152 in words is "six hundred thirty-eight billion, four hundred twenty-one million, five hundred forty-one thousand, one hundred fifty-two".