638122105776 has 160 divisors (see below), whose sum is σ = 1717669437120. Its totient is φ = 203890176000.

The previous prime is 638122105771. The next prime is 638122105783. The reversal of 638122105776 is 677501221836.

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 (638122105771) 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 31 ways as a sum of consecutive naturals, for example, 176616546 + ... + 176620158.

It is an arithmetic number, because the mean of its divisors is an integer number (10735433982).

Almost surely, 2^638122105776 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 638122105776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (858834718560).

638122105776 is an abundant number, since it is smaller than the sum of its proper divisors (1079547331344).

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

638122105776 is a wasteful number, since it uses less digits than its factorization.

638122105776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4535 (or 4529 counting only the distinct ones).

The product of its (nonzero) digits is 846720, while the sum is 48.

The spelling of 638122105776 in words is "six hundred thirty-eight billion, one hundred twenty-two million, one hundred five thousand, seven hundred seventy-six".