997855986 has 16 divisors (see below), whose sum is σ = 1997347968. Its totient is φ = 332346000.

The previous prime is 997855981. The next prime is 997856017. The reversal of 997855986 is 689558799.

It is not an unprimeable number, because it can be changed into a prime (997855981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60165 + ... + 74936.

It is an arithmetic number, because the mean of its divisors is an integer number (124834248).

Almost surely, 2^997855986 is an apocalyptic number.

997855986 is an abundant number, since it is smaller than the sum of its proper divisors (999491982).

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

997855986 is a wasteful number, since it uses less digits than its factorization.

997855986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136337.

The product of its digits is 48988800, while the sum is 66.

The square root of 997855986 is about 31588.8585738706. The cubic root of 997855986 is about 999.2848173023.

The spelling of 997855986 in words is "nine hundred ninety-seven million, eight hundred fifty-five thousand, nine hundred eighty-six".