638343836 has 48 divisors (see below), whose sum is σ = 1279088160. Its totient is φ = 276307200.

The previous prime is 638343803. The next prime is 638343841.

638343836 is nontrivially palindromic in base 10.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 96590 + ... + 102986.

It is an arithmetic number, because the mean of its divisors is an integer number (26647670).

Almost surely, 2^638343836 is an apocalyptic number.

It is an amenable number.

638343836 is an abundant number, since it is smaller than the sum of its proper divisors (640744324).

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

638343836 is a wasteful number, since it uses less digits than its factorization.

638343836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6534 (or 6532 counting only the distinct ones).

The product of its digits is 746496, while the sum is 44.

The square root of 638343836 is about 25265.4672626492. The cubic root of 638343836 is about 861.0298803055.

The spelling of 638343836 in words is "six hundred thirty-eight million, three hundred forty-three thousand, eight hundred thirty-six".