491905369 has 2 divisors, whose sum is σ = 491905370. Its totient is φ = 491905368.

The previous prime is 491905339. The next prime is 491905373. The reversal of 491905369 is 963509194.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 416649744 + 75255625 = 20412^2 + 8675^2 .

It is a cyclic number.

It is not a de Polignac number, because 491905369 - 2⁹ = 491904857 is a prime.

It is a super-2 number, since 2×491905369² = 483941784102052322, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (491905339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245952684 + 245952685.

It is an arithmetic number, because the mean of its divisors is an integer number (245952685).

Almost surely, 2^491905369 is an apocalyptic number.

It is an amenable number.

491905369 is a deficient number, since it is larger than the sum of its proper divisors (1).

491905369 is an equidigital number, since it uses as much as digits as its factorization.

491905369 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 262440, while the sum is 46.

The square root of 491905369 is about 22178.9397627569. The cubic root of 491905369 is about 789.3940602715.

The spelling of 491905369 in words is "four hundred ninety-one million, nine hundred five thousand, three hundred sixty-nine".