638863467815 has 16 divisors (see below), whose sum is σ = 776370355200. Its totient is φ = 504640524960.

The previous prime is 638863467793. The next prime is 638863467871. The reversal of 638863467815 is 518764368836.

It is a happy number.

It is not a de Polignac number, because 638863467815 - 2⁸ = 638863467559 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 (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2320319 + ... + 2581008.

It is an arithmetic number, because the mean of its divisors is an integer number (48523147200).

Almost surely, 2^638863467815 is an apocalyptic number.

638863467815 is a deficient number, since it is larger than the sum of its proper divisors (137506887385).

638863467815 is a wasteful number, since it uses less digits than its factorization.

638863467815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4901662.

The product of its digits is 139345920, while the sum is 65.

The spelling of 638863467815 in words is "six hundred thirty-eight billion, eight hundred sixty-three million, four hundred sixty-seven thousand, eight hundred fifteen".