638888132 has 6 divisors (see below), whose sum is σ = 1118054238. Its totient is φ = 319444064.

The previous prime is 638888113. The next prime is 638888141. The reversal of 638888132 is 231888836.

It can be written as a sum of positive squares in only one way, i.e., 565203076 + 73685056 = 23774^2 + 8584^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79861013 + ... + 79861020.

It is an arithmetic number, because the mean of its divisors is an integer number (186342373).

Almost surely, 2^638888132 is an apocalyptic number.

It is an amenable number.

638888132 is a deficient number, since it is larger than the sum of its proper divisors (479166106).

638888132 is a wasteful number, since it uses less digits than its factorization.

638888132 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159722037 (or 159722035 counting only the distinct ones).

The product of its digits is 442368, while the sum is 47.

The square root of 638888132 is about 25276.2365078348. The cubic root of 638888132 is about 861.2745352776.

The spelling of 638888132 in words is "six hundred thirty-eight million, eight hundred eighty-eight thousand, one hundred thirty-two".