91128133 has 2 divisors, whose sum is σ = 91128134. Its totient is φ = 91128132.

The previous prime is 91128131. The next prime is 91128203. The reversal of 91128133 is 33182119.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54863649 + 36264484 = 7407^2 + 6022^2 .

It is a cyclic number.

It is not a de Polignac number, because 91128133 - 2¹ = 91128131 is a prime.

Together with 91128131, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91128131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45564066 + 45564067.

It is an arithmetic number, because the mean of its divisors is an integer number (45564067).

Almost surely, 2^91128133 is an apocalyptic number.

It is an amenable number.

91128133 is a deficient number, since it is larger than the sum of its proper divisors (1).

91128133 is an equidigital number, since it uses as much as digits as its factorization.

91128133 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1296, while the sum is 28.

The square root of 91128133 is about 9546.1056457594. The cubic root of 91128133 is about 450.0051571425.

The spelling of 91128133 in words is "ninety-one million, one hundred twenty-eight thousand, one hundred thirty-three".