638155551836 has 12 divisors (see below), whose sum is σ = 1218296962680. Its totient is φ = 290070705360.

The previous prime is 638155551829. The next prime is 638155551889.

It is a happy number.

638155551836 is nontrivially palindromic in base 10.

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 3 ways as a sum of consecutive naturals, for example, 7251767591 + ... + 7251767678.

It is an arithmetic number, because the mean of its divisors is an integer number (101524746890).

Almost surely, 2^638155551836 is an apocalyptic number.

It is an amenable number.

638155551836 is a deficient number, since it is larger than the sum of its proper divisors (580141410844).

638155551836 is a wasteful number, since it uses less digits than its factorization.

638155551836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14503535284 (or 14503535282 counting only the distinct ones).

The product of its digits is 12960000, while the sum is 56.

The spelling of 638155551836 in words is "six hundred thirty-eight billion, one hundred fifty-five million, five hundred fifty-one thousand, eight hundred thirty-six".