638613621715 has 8 divisors (see below), whose sum is σ = 767807244288. Its totient is φ = 509910298560.

The previous prime is 638613621691. The next prime is 638613621757. The reversal of 638613621715 is 517126316836.

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

It is a de Polignac number, because none of the positive numbers 2^k-638613621715 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 122571987 + ... + 122577196.

It is an arithmetic number, because the mean of its divisors is an integer number (95975905536).

Almost surely, 2^638613621715 is an apocalyptic number.

638613621715 is a deficient number, since it is larger than the sum of its proper divisors (129193622573).

638613621715 is a wasteful number, since it uses less digits than its factorization.

638613621715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245149709.

The product of its digits is 1088640, while the sum is 49.

The spelling of 638613621715 in words is "six hundred thirty-eight billion, six hundred thirteen million, six hundred twenty-one thousand, seven hundred fifteen".