819997258368 has 128 divisors (see below), whose sum is σ = 2237692320000. Its totient is φ = 265861066752.

The previous prime is 819997258337. The next prime is 819997258387. The reversal of 819997258368 is 863852799918.

819997258368 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Cunningham number, because it is equal to 905537²-1.

It is a tau number, because it is divible by the number of its divisors (128).

It is a self number, because there is not a number n which added to its sum of digits gives 819997258368.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57947358 + ... + 57961506.

It is an arithmetic number, because the mean of its divisors is an integer number (17481971250).

Almost surely, 2^819997258368 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 819997258368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1118846160000).

819997258368 is an abundant number, since it is smaller than the sum of its proper divisors (1417695061632).

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

819997258368 is a wasteful number, since it uses less digits than its factorization.

819997258368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18282 (or 18270 counting only the distinct ones).

The product of its digits is 470292480, while the sum is 75.

The spelling of 819997258368 in words is "eight hundred nineteen billion, nine hundred ninety-seven million, two hundred fifty-eight thousand, three hundred sixty-eight".