817128726400 has 384 divisors, whose sum is σ = 2345971276800. Its totient is φ = 275448176640.

The previous prime is 817128726343. The next prime is 817128726419. The reversal of 817128726400 is 4627821718.

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 490178367 + ... + 490180033.

It is an arithmetic number, because the mean of its divisors is an integer number (6109300200).

Almost surely, 2^817128726400 is an apocalyptic number.

817128726400 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 817128726400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1172985638400).

817128726400 is an abundant number, since it is smaller than the sum of its proper divisors (1528842550400).

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

817128726400 is a wasteful number, since it uses less digits than its factorization.

817128726400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2054 (or 2037 counting only the distinct ones).

The product of its (nonzero) digits is 301056, while the sum is 46.

The spelling of 817128726400 in words is "eight hundred seventeen billion, one hundred twenty-eight million, seven hundred twenty-six thousand, four hundred".