638634321546 has 64 divisors (see below), whose sum is σ = 1385869201920. Its totient is φ = 195029176320.

The previous prime is 638634321449. The next prime is 638634321551. The reversal of 638634321546 is 645123436836.

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 31 ways as a sum of consecutive naturals, for example, 6439060 + ... + 6537488.

It is an arithmetic number, because the mean of its divisors is an integer number (21654206280).

Almost surely, 2^638634321546 is an apocalyptic number.

638634321546 is an abundant number, since it is smaller than the sum of its proper divisors (747234880374).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

638634321546 is a wasteful number, since it uses less digits than its factorization.

638634321546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99071.

The product of its digits is 7464960, while the sum is 51.

The spelling of 638634321546 in words is "six hundred thirty-eight billion, six hundred thirty-four million, three hundred twenty-one thousand, five hundred forty-six".