638343272 has 16 divisors (see below), whose sum is σ = 1367878560. Its totient is φ = 273575664.

The previous prime is 638343271. The next prime is 638343301. The reversal of 638343272 is 272343836.

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

It is not an unprimeable number, because it can be changed into a prime (638343271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5699438 + ... + 5699549.

It is an arithmetic number, because the mean of its divisors is an integer number (85492410).

Almost surely, 2^638343272 is an apocalyptic number.

It is an amenable number.

638343272 is an abundant number, since it is smaller than the sum of its proper divisors (729535288).

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

638343272 is a wasteful number, since it uses less digits than its factorization.

638343272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11399000 (or 11398996 counting only the distinct ones).

The product of its digits is 145152, while the sum is 38.

The square root of 638343272 is about 25265.4561011671. The cubic root of 638343272 is about 861.0296267217.

The spelling of 638343272 in words is "six hundred thirty-eight million, three hundred forty-three thousand, two hundred seventy-two".