998635769856 has 156 divisors (see below), whose sum is σ = 2892898199100. Its totient is φ = 331920506880.

The previous prime is 998635769851. The next prime is 998635769863. The reversal of 998635769856 is 658967536899.

It can be written as a sum of positive squares in 2 ways, for example, as 694355558400 + 304280211456 = 833280^2 + 551616^2 .

It is not an unprimeable number, because it can be changed into a prime (998635769851) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12826726 + ... + 12904346.

It is an arithmetic number, because the mean of its divisors is an integer number (18544219225).

Almost surely, 2^998635769856 is an apocalyptic number.

998635769856 is a gapful number since it is divisible by the number (96) 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 998635769856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1446449099550).

998635769856 is an abundant number, since it is smaller than the sum of its proper divisors (1894262429244).

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

998635769856 is a wasteful number, since it uses less digits than its factorization.

998635769856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78000 (or 77975 counting only the distinct ones).

The product of its digits is 5290790400, while the sum is 81.

The spelling of 998635769856 in words is "nine hundred ninety-eight billion, six hundred thirty-five million, seven hundred sixty-nine thousand, eight hundred fifty-six".