638685568015 has 32 divisors (see below), whose sum is σ = 885707784000. Its totient is φ = 436963737600.

The previous prime is 638685568009. The next prime is 638685568109. The reversal of 638685568015 is 510865586836.

It is not a de Polignac number, because 638685568015 - 2¹³ = 638685559823 is a prime.

It is a congruent number.

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 31 ways as a sum of consecutive naturals, for example, 1781611 + ... + 2109859.

It is an arithmetic number, because the mean of its divisors is an integer number (27678368250).

Almost surely, 2^638685568015 is an apocalyptic number.

638685568015 is a deficient number, since it is larger than the sum of its proper divisors (247022215985).

638685568015 is a wasteful number, since it uses less digits than its factorization.

638685568015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330363.

The product of its (nonzero) digits is 41472000, while the sum is 61.

The spelling of 638685568015 in words is "six hundred thirty-eight billion, six hundred eighty-five million, five hundred sixty-eight thousand, fifteen".