6891988891986 has 24 divisors (see below), whose sum is σ = 16290155563344. Its totient is φ = 2088481482360.

The previous prime is 6891988891969. The next prime is 6891988892029.

6891988891986 is nontrivially palindromic in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 6891988891896 and 6891988891905.

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 11 ways as a sum of consecutive naturals, for example, 17404012156 + ... + 17404012551.

It is an arithmetic number, because the mean of its divisors is an integer number (678756481806).

Almost surely, 2^{6891988891986} is an apocalyptic number.

6891988891986 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

6891988891986 is an abundant number, since it is smaller than the sum of its proper divisors (9398166671358).

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

6891988891986 is a wasteful number, since it uses less digits than its factorization.

6891988891986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34808024726 (or 34808024723 counting only the distinct ones).

The product of its digits is 7739670528, while the sum is 90.

The spelling of 6891988891986 in words is "six trillion, eight hundred ninety-one billion, nine hundred eighty-eight million, eight hundred ninety-one thousand, nine hundred eighty-six".