491001289 has 2 divisors, whose sum is σ = 491001290. Its totient is φ = 491001288.

The previous prime is 491001271. The next prime is 491001319. The reversal of 491001289 is 982100194.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 325441600 + 165559689 = 18040^2 + 12867^2 .

It is a cyclic number.

It is not a de Polignac number, because 491001289 - 2⁹ = 491000777 is a prime.

It is not a weakly prime, because it can be changed into another prime (491001229) 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, 245500644 + 245500645.

It is an arithmetic number, because the mean of its divisors is an integer number (245500645).

Almost surely, 2^491001289 is an apocalyptic number.

It is an amenable number.

491001289 is a deficient number, since it is larger than the sum of its proper divisors (1).

491001289 is an equidigital number, since it uses as much as digits as its factorization.

491001289 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 491001289 is about 22158.5488920191. The cubic root of 491001289 is about 788.9101507645.

The spelling of 491001289 in words is "four hundred ninety-one million, one thousand, two hundred eighty-nine".