638405134752 has 384 divisors, whose sum is σ = 2110348670976. Its totient is φ = 164160000000.

The previous prime is 638405134751. The next prime is 638405134789. The reversal of 638405134752 is 257431504836.

It is a super-2 number, since 2×638405134752² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (638405134751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 335825002 + ... + 335826902.

It is an arithmetic number, because the mean of its divisors is an integer number (5495699664).

Almost surely, 2^638405134752 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 638405134752, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1055174335488).

638405134752 is an abundant number, since it is smaller than the sum of its proper divisors (1471943536224).

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

638405134752 is a wasteful number, since it uses less digits than its factorization.

638405134752 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2364 (or 2356 counting only the distinct ones).

The product of its (nonzero) digits is 2419200, while the sum is 48.

The spelling of 638405134752 in words is "six hundred thirty-eight billion, four hundred five million, one hundred thirty-four thousand, seven hundred fifty-two".