638518201011 has 6 divisors (see below), whose sum is σ = 922304068140. Its totient is φ = 425678800668.

The previous prime is 638518201007. The next prime is 638518201021. The reversal of 638518201011 is 110102815836.

638518201011 is a `hidden beast` number, since 6 + 38 + 518 + 2 + 0 + 101 + 1 = 666.

It is not a de Polignac number, because 638518201011 - 2² = 638518201007 is a prime.

It is not an unprimeable number, because it can be changed into a prime (638518201021) 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 5 ways as a sum of consecutive naturals, for example, 35473233381 + ... + 35473233398.

It is an arithmetic number, because the mean of its divisors is an integer number (153717344690).

Almost surely, 2^638518201011 is an apocalyptic number.

638518201011 is a deficient number, since it is larger than the sum of its proper divisors (283785867129).

638518201011 is a wasteful number, since it uses less digits than its factorization.

638518201011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70946466785 (or 70946466782 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The spelling of 638518201011 in words is "six hundred thirty-eight billion, five hundred eighteen million, two hundred one thousand, eleven".