99991986 has 16 divisors (see below), whose sum is σ = 200210400. Its totient is φ = 33292928.

The previous prime is 99991981. The next prime is 99991987. The reversal of 99991986 is 68919999.

It is not an unprimeable number, because it can be changed into a prime (99991981) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3396 + ... + 14543.

It is an arithmetic number, because the mean of its divisors is an integer number (12513150).

Almost surely, 2^99991986 is an apocalyptic number.

99991986 is an abundant number, since it is smaller than the sum of its proper divisors (100218414).

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

99991986 is a wasteful number, since it uses less digits than its factorization.

99991986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18873.

The product of its digits is 2834352, while the sum is 60.

The square root of 99991986 is about 9999.5992919717. The cubic root of 99991986 is about 464.1464837991.

The spelling of 99991986 in words is "ninety-nine million, nine hundred ninety-one thousand, nine hundred eighty-six".