638902238 has 8 divisors (see below), whose sum is σ = 1032072888. Its totient is φ = 294877944.

The previous prime is 638902193. The next prime is 638902247. The reversal of 638902238 is 832209836.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 638902195 and 638902204.

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, 12286556 + ... + 12286607.

It is an arithmetic number, because the mean of its divisors is an integer number (129009111).

Almost surely, 2^638902238 is an apocalyptic number.

638902238 is a deficient number, since it is larger than the sum of its proper divisors (393170650).

638902238 is a wasteful number, since it uses less digits than its factorization.

638902238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24573178.

The product of its (nonzero) digits is 124416, while the sum is 41.

The square root of 638902238 is about 25276.5155430886. The cubic root of 638902238 is about 861.2808739195.

The spelling of 638902238 in words is "six hundred thirty-eight million, nine hundred two thousand, two hundred thirty-eight".