638942241 has 16 divisors (see below), whose sum is σ = 1024870400. Its totient is φ = 345893328.

The previous prime is 638942219. The next prime is 638942267. The reversal of 638942241 is 142249836.

It is not a de Polignac number, because 638942241 - 2⁷ = 638942113 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 638942241.

It is not an unprimeable number, because it can be changed into a prime (638942281) 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 15 ways as a sum of consecutive naturals, for example, 800281 + ... + 801078.

It is an arithmetic number, because the mean of its divisors is an integer number (64054400).

Almost surely, 2^638942241 is an apocalyptic number.

It is an amenable number.

638942241 is a deficient number, since it is larger than the sum of its proper divisors (385928159).

638942241 is a wasteful number, since it uses less digits than its factorization.

638942241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1601388.

The product of its digits is 82944, while the sum is 39.

The square root of 638942241 is about 25277.3068383481. The cubic root of 638942241 is about 861.2988490742.

The spelling of 638942241 in words is "six hundred thirty-eight million, nine hundred forty-two thousand, two hundred forty-one".