638396503 has 4 divisors (see below), whose sum is σ = 638456848. Its totient is φ = 638336160.

The previous prime is 638396497. The next prime is 638396513. The reversal of 638396503 is 305693836.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 638396503 - 2¹⁷ = 638265431 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 638396503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638396513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9651 + ... + 37012.

It is an arithmetic number, because the mean of its divisors is an integer number (159614212).

Almost surely, 2^638396503 is an apocalyptic number.

638396503 is a deficient number, since it is larger than the sum of its proper divisors (60345).

638396503 is a wasteful number, since it uses less digits than its factorization.

638396503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60344.

The product of its (nonzero) digits is 349920, while the sum is 43.

The square root of 638396503 is about 25266.5095135834. The cubic root of 638396503 is about 861.0535596097.

The spelling of 638396503 in words is "six hundred thirty-eight million, three hundred ninety-six thousand, five hundred three".