638826256257 has 32 divisors (see below), whose sum is σ = 976009036800. Its totient is φ = 364084193088.

The previous prime is 638826256249. The next prime is 638826256307. The reversal of 638826256257 is 752652628836.

It is a happy number.

It is not a de Polignac number, because 638826256257 - 2³ = 638826256249 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 638826256257.

It is not an unprimeable number, because it can be changed into a prime (638826256157) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 58393494 + ... + 58404432.

It is an arithmetic number, because the mean of its divisors is an integer number (30500282400).

Almost surely, 2^638826256257 is an apocalyptic number.

It is an amenable number.

638826256257 is a deficient number, since it is larger than the sum of its proper divisors (337182780543).

638826256257 is a wasteful number, since it uses less digits than its factorization.

638826256257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18005.

The product of its digits is 58060800, while the sum is 60.

The spelling of 638826256257 in words is "six hundred thirty-eight billion, eight hundred twenty-six million, two hundred fifty-six thousand, two hundred fifty-seven".