638763267424128 has 4096 divisors, whose sum is σ = 2418683535360000. Its totient is φ = 148712752742400.

The previous prime is 638763267424127. The next prime is 638763267424159. The reversal of 638763267424128 is 821424762367836.

It is a happy number.

638763267424128 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638763267424123) by changing a digit.

It is a polite number, since it can be written in 511 ways as a sum of consecutive naturals, for example, 8750181745500 + ... + 8750181745572.

It is an arithmetic number, because the mean of its divisors is an integer number (590498910000).

Almost surely, 2^{638763267424128} 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 638763267424128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1209341767680000).

638763267424128 is an abundant number, since it is smaller than the sum of its proper divisors (1779920267935872).

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

638763267424128 is a wasteful number, since it uses less digits than its factorization.

638763267424128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271 (or 223 counting only the distinct ones).

The product of its digits is 780337152, while the sum is 69.

The spelling of 638763267424128 in words is "six hundred thirty-eight trillion, seven hundred sixty-three billion, two hundred sixty-seven million, four hundred twenty-four thousand, one hundred twenty-eight".