638225236 has 24 divisors (see below), whose sum is σ = 1225740096. Its totient is φ = 288361920.

The previous prime is 638225209. The next prime is 638225239. The reversal of 638225236 is 632522836.

It is a junction number, because it is equal to n+sod(n) for n = 638225195 and 638225204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638225239) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36081 + ... + 50776.

It is an arithmetic number, because the mean of its divisors is an integer number (51072504).

Almost surely, 2^638225236 is an apocalyptic number.

It is an amenable number.

638225236 is a deficient number, since it is larger than the sum of its proper divisors (587514860).

638225236 is a wasteful number, since it uses less digits than its factorization.

638225236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87039 (or 87037 counting only the distinct ones).

The product of its digits is 103680, while the sum is 37.

The square root of 638225236 is about 25263.1200765068. The cubic root of 638225236 is about 860.9765524786.

The spelling of 638225236 in words is "six hundred thirty-eight million, two hundred twenty-five thousand, two hundred thirty-six".