638902269 has 8 divisors (see below), whose sum is σ = 946521920. Its totient is φ = 425934828.

The previous prime is 638902267. The next prime is 638902289. The reversal of 638902269 is 962209836.

638902269 is a `hidden beast` number, since 6 + 389 + 0 + 2 + 269 = 666.

It is not a de Polignac number, because 638902269 - 2¹ = 638902267 is a prime.

It is a super-2 number, since 2×638902269² = 816392218666696722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638902261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11831497 + ... + 11831550.

It is an arithmetic number, because the mean of its divisors is an integer number (118315240).

Almost surely, 2^638902269 is an apocalyptic number.

It is an amenable number.

638902269 is a deficient number, since it is larger than the sum of its proper divisors (307619651).

638902269 is a wasteful number, since it uses less digits than its factorization.

638902269 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23663056 (or 23663050 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 45.

The square root of 638902269 is about 25276.5161563060. The cubic root of 638902269 is about 861.2808878495.

The spelling of 638902269 in words is "six hundred thirty-eight million, nine hundred two thousand, two hundred sixty-nine".