491580121 has 2 divisors, whose sum is σ = 491580122. Its totient is φ = 491580120.

The previous prime is 491580059. The next prime is 491580157. The reversal of 491580121 is 121085194.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 465006096 + 26574025 = 21564^2 + 5155^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-491580121 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (491580161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245790060 + 245790061.

It is an arithmetic number, because the mean of its divisors is an integer number (245790061).

Almost surely, 2^491580121 is an apocalyptic number.

It is an amenable number.

491580121 is a deficient number, since it is larger than the sum of its proper divisors (1).

491580121 is an equidigital number, since it uses as much as digits as its factorization.

491580121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 31.

The square root of 491580121 is about 22171.6061889977. The cubic root of 491580121 is about 789.2200393698.

The spelling of 491580121 in words is "four hundred ninety-one million, five hundred eighty thousand, one hundred twenty-one".