91991425133 has 4 divisors (see below), whose sum is σ = 91992167328. Its totient is φ = 91990682940.

The previous prime is 91991425093. The next prime is 91991425139. The reversal of 91991425133 is 33152419919.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 91991425133 - 2¹⁶ = 91991359597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91991425139) 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 3 ways as a sum of consecutive naturals, for example, 135191 + ... + 449732.

It is an arithmetic number, because the mean of its divisors is an integer number (22998041832).

Almost surely, 2^91991425133 is an apocalyptic number.

It is an amenable number.

91991425133 is a deficient number, since it is larger than the sum of its proper divisors (742195).

91991425133 is a wasteful number, since it uses less digits than its factorization.

91991425133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 742194.

The product of its digits is 262440, while the sum is 47.

The spelling of 91991425133 in words is "ninety-one billion, nine hundred ninety-one million, four hundred twenty-five thousand, one hundred thirty-three".