638820007782 has 32 divisors (see below), whose sum is σ = 1420087023360. Its totient is φ = 189929332320.

The previous prime is 638820007747. The next prime is 638820007783. The reversal of 638820007782 is 287700028836.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638820007783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 91308682 + ... + 91315677.

It is an arithmetic number, because the mean of its divisors is an integer number (44377719480).

Almost surely, 2^638820007782 is an apocalyptic number.

638820007782 is an abundant number, since it is smaller than the sum of its proper divisors (781267015578).

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

638820007782 is a wasteful number, since it uses less digits than its factorization.

638820007782 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182624428.

The product of its (nonzero) digits is 1806336, while the sum is 51.

The spelling of 638820007782 in words is "six hundred thirty-eight billion, eight hundred twenty million, seven thousand, seven hundred eighty-two".