991109903 has 8 divisors (see below), whose sum is σ = 1133489280. Its totient is φ = 848928600.

The previous prime is 991109891. The next prime is 991109909. The reversal of 991109903 is 309901199.

991109903 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 991109903 - 2²⁰ = 990061327 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991109909) 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, 38633 + ... + 58946.

It is an arithmetic number, because the mean of its divisors is an integer number (141686160).

Almost surely, 2^991109903 is an apocalyptic number.

991109903 is a deficient number, since it is larger than the sum of its proper divisors (142379377).

991109903 is a wasteful number, since it uses less digits than its factorization.

991109903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99037.

The product of its (nonzero) digits is 19683, while the sum is 41.

The square root of 991109903 is about 31481.8980209262. The cubic root of 991109903 is about 997.0278091670.

The spelling of 991109903 in words is "nine hundred ninety-one million, one hundred nine thousand, nine hundred three".