491133521 has 2 divisors, whose sum is σ = 491133522. Its totient is φ = 491133520.

The previous prime is 491133499. The next prime is 491133529. The reversal of 491133521 is 125331194.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 267780496 + 223353025 = 16364^2 + 14945^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-491133521 is a prime.

It is equal to p_25913027 and since 491133521 and 25913027 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 (491133529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245566760 + 245566761.

It is an arithmetic number, because the mean of its divisors is an integer number (245566761).

Almost surely, 2^491133521 is an apocalyptic number.

It is an amenable number.

491133521 is a deficient number, since it is larger than the sum of its proper divisors (1).

491133521 is an equidigital number, since it uses as much as digits as its factorization.

491133521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3240, while the sum is 29.

The square root of 491133521 is about 22161.5324605497. The cubic root of 491133521 is about 788.9809651093.

The spelling of 491133521 in words is "four hundred ninety-one million, one hundred thirty-three thousand, five hundred twenty-one".