638613637805 has 64 divisors (see below), whose sum is σ = 957081242880. Its totient is φ = 402133248000.

The previous prime is 638613637801. The next prime is 638613637829. The reversal of 638613637805 is 508736316836.

It is a happy number.

It is not a de Polignac number, because 638613637805 - 2² = 638613637801 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638613637801) by changing a digit.

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 63 ways as a sum of consecutive naturals, for example, 1139369 + ... + 1604801.

It is an arithmetic number, because the mean of its divisors is an integer number (14954394420).

Almost surely, 2^638613637805 is an apocalyptic number.

638613637805 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

638613637805 is a deficient number, since it is larger than the sum of its proper divisors (318467605075).

638613637805 is a wasteful number, since it uses less digits than its factorization.

638613637805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 465582.

The product of its (nonzero) digits is 13063680, while the sum is 56.

The spelling of 638613637805 in words is "six hundred thirty-eight billion, six hundred thirteen million, six hundred thirty-seven thousand, eight hundred five".