638865503122 has 64 divisors (see below), whose sum is σ = 1230245791488. Its totient is φ = 241579008000.

The previous prime is 638865503119. The next prime is 638865503131. The reversal of 638865503122 is 221305568836.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 956472 + ... + 1480732.

It is an arithmetic number, because the mean of its divisors is an integer number (19222590492).

Almost surely, 2^638865503122 is an apocalyptic number.

638865503122 is a deficient number, since it is larger than the sum of its proper divisors (591380288366).

638865503122 is a wasteful number, since it uses less digits than its factorization.

638865503122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 524515.

The product of its (nonzero) digits is 2073600, while the sum is 49.

The spelling of 638865503122 in words is "six hundred thirty-eight billion, eight hundred sixty-five million, five hundred three thousand, one hundred twenty-two".