491222657 has 2 divisors, whose sum is σ = 491222658. Its totient is φ = 491222656.

The previous prime is 491222623. The next prime is 491222671. The reversal of 491222657 is 756222194.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 488233216 + 2989441 = 22096^2 + 1729^2 .

It is a cyclic number.

It is not a de Polignac number, because 491222657 - 2⁶ = 491222593 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 491222657.

It is not a weakly prime, because it can be changed into another prime (491222687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245611328 + 245611329.

It is an arithmetic number, because the mean of its divisors is an integer number (245611329).

Almost surely, 2^491222657 is an apocalyptic number.

It is an amenable number.

491222657 is a deficient number, since it is larger than the sum of its proper divisors (1).

491222657 is an equidigital number, since it uses as much as digits as its factorization.

491222657 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60480, while the sum is 38.

The square root of 491222657 is about 22163.5434215741. The cubic root of 491222657 is about 789.0286930354.

The spelling of 491222657 in words is "four hundred ninety-one million, two hundred twenty-two thousand, six hundred fifty-seven".