638636081734 has 16 divisors (see below), whose sum is σ = 1094851231488. Its totient is φ = 273689547912.

The previous prime is 638636081719. The next prime is 638636081753. The reversal of 638636081734 is 437180636836.

It is a happy number.

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 7 ways as a sum of consecutive naturals, for example, 623674 + ... + 1290829.

It is an arithmetic number, because the mean of its divisors is an integer number (68428201968).

Almost surely, 2^638636081734 is an apocalyptic number.

638636081734 is a deficient number, since it is larger than the sum of its proper divisors (456215149754).

638636081734 is a wasteful number, since it uses less digits than its factorization.

638636081734 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1938339.

The product of its (nonzero) digits is 10450944, while the sum is 55.

The spelling of 638636081734 in words is "six hundred thirty-eight billion, six hundred thirty-six million, eighty-one thousand, seven hundred thirty-four".