91001009998 has 16 divisors (see below), whose sum is σ = 148640490000. Its totient is φ = 41619336192.

The previous prime is 91001009977. The next prime is 91001010007. The reversal of 91001009998 is 89990010019.

It is a congruent number.

It is an unprimeable number.

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, 41287923 + ... + 41290126.

It is an arithmetic number, because the mean of its divisors is an integer number (9290030625).

Almost surely, 2^91001009998 is an apocalyptic number.

91001009998 is a deficient number, since it is larger than the sum of its proper divisors (57639480002).

91001009998 is a wasteful number, since it uses less digits than its factorization.

91001009998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82578099.

The product of its (nonzero) digits is 52488, while the sum is 46.

The spelling of 91001009998 in words is "ninety-one billion, one million, nine thousand, nine hundred ninety-eight".