491851417 has 2 divisors, whose sum is σ = 491851418. Its totient is φ = 491851416.

The previous prime is 491851411. The next prime is 491851439. The reversal of 491851417 is 714158194.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 365153881 + 126697536 = 19109^2 + 11256^2 .

It is a cyclic number.

It is not a de Polignac number, because 491851417 - 2¹⁹ = 491327129 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 491851417.

It is not a weakly prime, because it can be changed into another prime (491851411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245925708 + 245925709.

It is an arithmetic number, because the mean of its divisors is an integer number (245925709).

Almost surely, 2^491851417 is an apocalyptic number.

It is an amenable number.

491851417 is a deficient number, since it is larger than the sum of its proper divisors (1).

491851417 is an equidigital number, since it uses as much as digits as its factorization.

491851417 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40320, while the sum is 40.

The square root of 491851417 is about 22177.7234404255. The cubic root of 491851417 is about 789.3651990662.

The spelling of 491851417 in words is "four hundred ninety-one million, eight hundred fifty-one thousand, four hundred seventeen".