991100009901 has 8 divisors (see below), whose sum is σ = 1321642226880. Its totient is φ = 660645566432.

The previous prime is 991100009873. The next prime is 991100009909. The reversal of 991100009901 is 109900001199.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-991100009901 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 991100009901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991100009909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21917025 + ... + 21962198.

It is an arithmetic number, because the mean of its divisors is an integer number (165205278360).

Almost surely, 2^991100009901 is an apocalyptic number.

It is an amenable number.

991100009901 is a deficient number, since it is larger than the sum of its proper divisors (330542216979).

991100009901 is a wasteful number, since it uses less digits than its factorization.

991100009901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43886755.

The product of its (nonzero) digits is 6561, while the sum is 39.

The spelling of 991100009901 in words is "nine hundred ninety-one billion, one hundred million, nine thousand, nine hundred one".