998678871666 has 40 divisors (see below), whose sum is σ = 2557463356800. Its totient is φ = 285336820152.

The previous prime is 998678871611. The next prime is 998678871679. The reversal of 998678871666 is 666178876899.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 440333466 + ... + 440335733.

It is an arithmetic number, because the mean of its divisors is an integer number (63936583920).

Almost surely, 2^998678871666 is an apocalyptic number.

998678871666 is an abundant number, since it is smaller than the sum of its proper divisors (1558784485134).

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

998678871666 is a wasteful number, since it uses less digits than its factorization.

998678871666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 880669220 (or 880669211 counting only the distinct ones).

The product of its digits is 2633637888, while the sum is 81.

The spelling of 998678871666 in words is "nine hundred ninety-eight billion, six hundred seventy-eight million, eight hundred seventy-one thousand, six hundred sixty-six".