9991408 has 20 divisors (see below), whose sum is σ = 22124080.
Its totient is φ = 4281984.
The previous prime is 9991379. The next prime is 9991409. The reversal of 9991408 is 8041999.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (9991409) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (11) of ones.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44493 + ... + 44716.
It is an arithmetic number, because the mean of its divisors is an integer number (1106204).
Almost surely, 29991408 is an apocalyptic number.
It is an amenable number.
9991408 is an abundant number, since it is smaller than the sum of its proper divisors (12132672).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
9991408 is a wasteful number, since it uses less digits than its factorization.
9991408 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 89224 (or 89218 counting only the distinct ones).
The product of its (nonzero) digits is 23328, while the sum is 40.
The square root of 9991408 is about 3160.9188537512.
The cubic root of 9991408 is about 215.3817483135.
The spelling of 9991408 in words is "nine million, nine hundred ninety-one thousand, four hundred eight".