491161243 has 2 divisors, whose sum is σ = 491161244. Its totient is φ = 491161242.

The previous prime is 491161201. The next prime is 491161259. The reversal of 491161243 is 342161194.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 491161243 - 2⁹ = 491160731 is a prime.

It is equal to p_25914433 and since 491161243 and 25914433 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (491161043) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245580621 + 245580622.

It is an arithmetic number, because the mean of its divisors is an integer number (245580622).

Almost surely, 2^491161243 is an apocalyptic number.

491161243 is a deficient number, since it is larger than the sum of its proper divisors (1).

491161243 is an equidigital number, since it uses as much as digits as its factorization.

491161243 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5184, while the sum is 31.

The square root of 491161243 is about 22162.1579048612. The cubic root of 491161243 is about 788.9958094899.

The spelling of 491161243 in words is "four hundred ninety-one million, one hundred sixty-one thousand, two hundred forty-three".