638460089064 has 576 divisors, whose sum is σ = 2136214080000. Its totient is φ = 171491281920.

The previous prime is 638460089063. The next prime is 638460089083. The reversal of 638460089064 is 460980064836.

638460089064 is a `hidden beast` number, since 6 + 38 + 460 + 0 + 8 + 90 + 64 = 666.

It is a super-2 number, since 2×638460089064² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 638460089064.

It is not an unprimeable number, because it can be changed into a prime (638460089063) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1641285382 + ... + 1641285770.

It is an arithmetic number, because the mean of its divisors is an integer number (3708705000).

Almost surely, 2^638460089064 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638460089064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1068107040000).

638460089064 is an abundant number, since it is smaller than the sum of its proper divisors (1497753990936).

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

638460089064 is a wasteful number, since it uses less digits than its factorization.

638460089064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 838 (or 824 counting only the distinct ones).

The product of its (nonzero) digits is 5971968, while the sum is 54.

The spelling of 638460089064 in words is "six hundred thirty-eight billion, four hundred sixty million, eighty-nine thousand, sixty-four".