638378455265 has 8 divisors (see below), whose sum is σ = 773638841448. Its totient is φ = 505646300800.

The previous prime is 638378455259. The next prime is 638378455289. The reversal of 638378455265 is 562554873836.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 355602312976 + 282776142289 = 596324^2 + 531767^2 .

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

It is not a de Polignac number, because 638378455265 - 2¹⁸ = 638378193121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 638378455198 and 638378455207.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 632057372 + ... + 632058381.

It is an arithmetic number, because the mean of its divisors is an integer number (96704855181).

Almost surely, 2^638378455265 is an apocalyptic number.

It is an amenable number.

638378455265 is a deficient number, since it is larger than the sum of its proper divisors (135260386183).

638378455265 is a wasteful number, since it uses less digits than its factorization.

638378455265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1264115859.

The product of its digits is 145152000, while the sum is 62.

The spelling of 638378455265 in words is "six hundred thirty-eight billion, three hundred seventy-eight million, four hundred fifty-five thousand, two hundred sixty-five".