491785313 has 2 divisors, whose sum is σ = 491785314. Its totient is φ = 491785312.

The previous prime is 491785309. The next prime is 491785319. The reversal of 491785313 is 313587194.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 336832609 + 154952704 = 18353^2 + 12448^2 .

It is a cyclic number.

It is not a de Polignac number, because 491785313 - 2² = 491785309 is a prime.

It is not a weakly prime, because it can be changed into another prime (491785319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245892656 + 245892657.

It is an arithmetic number, because the mean of its divisors is an integer number (245892657).

Almost surely, 2^491785313 is an apocalyptic number.

It is an amenable number.

491785313 is a deficient number, since it is larger than the sum of its proper divisors (1).

491785313 is an equidigital number, since it uses as much as digits as its factorization.

491785313 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90720, while the sum is 41.

The square root of 491785313 is about 22176.2330660552. The cubic root of 491785313 is about 789.3298343652.

The spelling of 491785313 in words is "four hundred ninety-one million, seven hundred eighty-five thousand, three hundred thirteen".