638513002 has 4 divisors (see below), whose sum is σ = 957769506. Its totient is φ = 319256500.

The previous prime is 638512991. The next prime is 638513017. The reversal of 638513002 is 200315836.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 396368281 + 242144721 = 19909^2 + 15561^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159628249 + ... + 159628252.

Almost surely, 2^638513002 is an apocalyptic number.

638513002 is a deficient number, since it is larger than the sum of its proper divisors (319256504).

638513002 is a wasteful number, since it uses less digits than its factorization.

638513002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319256503.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 638513002 is about 25268.8148119377. The cubic root of 638513002 is about 861.1059334228.

Adding to 638513002 its reverse (200315836), we get a palindrome (838828838).

The spelling of 638513002 in words is "six hundred thirty-eight million, five hundred thirteen thousand, two".