638454456873 has 6 divisors (see below), whose sum is σ = 922211993274. Its totient is φ = 425636304576.

The previous prime is 638454456863. The next prime is 638454456877. The reversal of 638454456873 is 378654454836.

It is a happy number.

638454456873 is a `hidden beast` number, since 6 + 3 + 8 + 4 + 544 + 5 + 6 + 87 + 3 = 666.

It can be written as a sum of positive squares in only one way, i.e., 451438859664 + 187015597209 = 671892^2 + 432453^2 .

It is a de Polignac number, because none of the positive numbers 2^k-638454456873 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 638454456873.

It is not an unprimeable number, because it can be changed into a prime (638454456877) 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, 35469692040 + ... + 35469692057.

It is an arithmetic number, because the mean of its divisors is an integer number (153701998879).

Almost surely, 2^638454456873 is an apocalyptic number.

It is an amenable number.

638454456873 is a deficient number, since it is larger than the sum of its proper divisors (283757536401).

638454456873 is a wasteful number, since it uses less digits than its factorization.

638454456873 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70939384103 (or 70939384100 counting only the distinct ones).

The product of its digits is 232243200, while the sum is 63.

The spelling of 638454456873 in words is "six hundred thirty-eight billion, four hundred fifty-four million, four hundred fifty-six thousand, eight hundred seventy-three".