638762065 has 8 divisors (see below), whose sum is σ = 769696488. Its totient is φ = 508888320.

The previous prime is 638762051. The next prime is 638762081. The reversal of 638762065 is 560267836.

It can be written as a sum of positive squares in 4 ways, for example, as 91623184 + 547138881 = 9572^2 + 23391^2 .

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

It is a de Polignac number, because none of the positive numbers 2^k-638762065 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 263842 + ... + 266251.

It is an arithmetic number, because the mean of its divisors is an integer number (96212061).

Almost surely, 2^638762065 is an apocalyptic number.

It is an amenable number.

638762065 is a deficient number, since it is larger than the sum of its proper divisors (130934423).

638762065 is a wasteful number, since it uses less digits than its factorization.

638762065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 530339.

The product of its (nonzero) digits is 362880, while the sum is 43.

The square root of 638762065 is about 25273.7425997813. The cubic root of 638762065 is about 861.2178819378.

The spelling of 638762065 in words is "six hundred thirty-eight million, seven hundred sixty-two thousand, sixty-five".