640813663333280 has 192 divisors, whose sum is σ = 1532809277153280. Its totient is φ = 253146539520000.

The previous prime is 640813663333267. The next prime is 640813663333343. The reversal of 640813663333280 is 82333366318046.

It is a happy number.

It is a super-2 number, since 2×640813663333280² (a number of 30 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 31181619005 + ... + 31181639555.

It is an arithmetic number, because the mean of its divisors is an integer number (7983381651840).

Almost surely, 2^{640813663333280} 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 640813663333280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (766404638576640).

640813663333280 is an abundant number, since it is smaller than the sum of its proper divisors (891995613820000).

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

640813663333280 is a wasteful number, since it uses less digits than its factorization.

640813663333280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27623 (or 27615 counting only the distinct ones).

The product of its (nonzero) digits is 26873856, while the sum is 56.

The spelling of 640813663333280 in words is "six hundred forty trillion, eight hundred thirteen billion, six hundred sixty-three million, three hundred thirty-three thousand, two hundred eighty".