638357853505 has 8 divisors (see below), whose sum is σ = 766044260712. Its totient is φ = 510676391808.

The previous prime is 638357853481. The next prime is 638357853547. The reversal of 638357853505 is 505358753836.

It can be written as a sum of positive squares in 4 ways, for example, as 136646297649 + 501711555856 = 369657^2 + 708316^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 638357853505 - 2⁷ = 638357853377 is a prime.

It is a super-2 number, since 2×638357853505² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 638357853505.

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 in 7 ways as a sum of consecutive naturals, for example, 946212 + ... + 1473781.

It is an arithmetic number, because the mean of its divisors is an integer number (95755532589).

Almost surely, 2^638357853505 is an apocalyptic number.

It is an amenable number.

638357853505 is a deficient number, since it is larger than the sum of its proper divisors (127686407207).

638357853505 is a wasteful number, since it uses less digits than its factorization.

638357853505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2472755.

The product of its (nonzero) digits is 45360000, while the sum is 58.

The spelling of 638357853505 in words is "six hundred thirty-eight billion, three hundred fifty-seven million, eight hundred fifty-three thousand, five hundred five".