91005289 has 2 divisors, whose sum is σ = 91005290. Its totient is φ = 91005288.

The previous prime is 91005263. The next prime is 91005331. The reversal of 91005289 is 98250019.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72386064 + 18619225 = 8508^2 + 4315^2 .

It is a cyclic number.

It is not a de Polignac number, because 91005289 - 2⁹ = 91004777 is a prime.

It is not a weakly prime, because it can be changed into another prime (91005209) 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, 45502644 + 45502645.

It is an arithmetic number, because the mean of its divisors is an integer number (45502645).

Almost surely, 2^91005289 is an apocalyptic number.

It is an amenable number.

91005289 is a deficient number, since it is larger than the sum of its proper divisors (1).

91005289 is an equidigital number, since it uses as much as digits as its factorization.

91005289 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6480, while the sum is 34.

The square root of 91005289 is about 9539.6692290666. The cubic root of 91005289 is about 449.8028585024.

It can be divided in two parts, 910052 and 89, that multiplied together give a triangular number (80994628 = T₁₂₇₂₇).

The spelling of 91005289 in words is "ninety-one million, five thousand, two hundred eighty-nine".