91991003 has 16 divisors (see below), whose sum is σ = 102495456. Its totient is φ = 82018560.

The previous prime is 91990999. The next prime is 91991041. The reversal of 91991003 is 30019919.

It is not a de Polignac number, because 91991003 - 2² = 91990999 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91991083) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 56225 + ... + 57837.

It is an arithmetic number, because the mean of its divisors is an integer number (6405966).

Almost surely, 2^91991003 is an apocalyptic number.

91991003 is a deficient number, since it is larger than the sum of its proper divisors (10504453).

91991003 is a wasteful number, since it uses less digits than its factorization.

91991003 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1774.

The product of its (nonzero) digits is 2187, while the sum is 32.

The square root of 91991003 is about 9591.1940341127. The cubic root of 91991003 is about 451.4210272438.

The spelling of 91991003 in words is "ninety-one million, nine hundred ninety-one thousand, three".