638223388 has 12 divisors (see below), whose sum is σ = 1218426552. Its totient is φ = 290101520.

The previous prime is 638223373. The next prime is 638223407. The reversal of 638223388 is 883322836.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7252495 + ... + 7252582.

It is an arithmetic number, because the mean of its divisors is an integer number (101535546).

Almost surely, 2^638223388 is an apocalyptic number.

It is an amenable number.

638223388 is a deficient number, since it is larger than the sum of its proper divisors (580203164).

638223388 is a wasteful number, since it uses less digits than its factorization.

638223388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14505092 (or 14505090 counting only the distinct ones).

The product of its digits is 331776, while the sum is 43.

The square root of 638223388 is about 25263.0835014256. The cubic root of 638223388 is about 860.9757214834.

The spelling of 638223388 in words is "six hundred thirty-eight million, two hundred twenty-three thousand, three hundred eighty-eight".