91128377 has 2 divisors, whose sum is σ = 91128378. Its totient is φ = 91128376.

The previous prime is 91128371. The next prime is 91128379. The reversal of 91128377 is 77382119.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61795321 + 29333056 = 7861^2 + 5416^2 .

It is a cyclic number.

It is not a de Polignac number, because 91128377 - 2¹² = 91124281 is a prime.

Together with 91128379, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 91128377.

It is not a weakly prime, because it can be changed into another prime (91128371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45564188 + 45564189.

It is an arithmetic number, because the mean of its divisors is an integer number (45564189).

Almost surely, 2^91128377 is an apocalyptic number.

It is an amenable number.

91128377 is a deficient number, since it is larger than the sum of its proper divisors (1).

91128377 is an equidigital number, since it uses as much as digits as its factorization.

91128377 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21168, while the sum is 38.

The square root of 91128377 is about 9546.1184258315. The cubic root of 91128377 is about 450.0055587791.

The spelling of 91128377 in words is "ninety-one million, one hundred twenty-eight thousand, three hundred seventy-seven".