998887777777 has 4 divisors (see below), whose sum is σ = 1008051885940. Its totient is φ = 989723669616.

The previous prime is 998887777739. The next prime is 998887777807. The reversal of 998887777777 is 777777788899.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 853916453776 + 144971324001 = 924076^2 + 380751^2 .

It is a cyclic number.

It is not a de Polignac number, because 998887777777 - 2¹¹ = 998887775729 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 998887777691 and 998887777700.

It is not an unprimeable number, because it can be changed into a prime (998887777477) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4582053918 + ... + 4582054135.

It is an arithmetic number, because the mean of its divisors is an integer number (252012971485).

Almost surely, 2^998887777777 is an apocalyptic number.

It is an amenable number.

998887777777 is a deficient number, since it is larger than the sum of its proper divisors (9164108163).

998887777777 is a wasteful number, since it uses less digits than its factorization.

998887777777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9164108162.

The product of its digits is 34153975296, while the sum is 91.

The spelling of 998887777777 in words is "nine hundred ninety-eight billion, eight hundred eighty-seven million, seven hundred seventy-seven thousand, seven hundred seventy-seven".