491451872881 has 2 divisors, whose sum is σ = 491451872882. Its totient is φ = 491451872880.

The previous prime is 491451872867. The next prime is 491451872971. The reversal of 491451872881 is 188278154194.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 472781383281 + 18670489600 = 687591^2 + 136640^2 .

It is a cyclic number.

It is not a de Polignac number, because 491451872881 - 2³³ = 482861938289 is a prime.

It is a super-2 number, since 2×491451872881² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (491451872801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245725936440 + 245725936441.

It is an arithmetic number, because the mean of its divisors is an integer number (245725936441).

Almost surely, 2^491451872881 is an apocalyptic number.

It is an amenable number.

491451872881 is a deficient number, since it is larger than the sum of its proper divisors (1).

491451872881 is an equidigital number, since it uses as much as digits as its factorization.

491451872881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5160960, while the sum is 58.

The spelling of 491451872881 in words is "four hundred ninety-one billion, four hundred fifty-one million, eight hundred seventy-two thousand, eight hundred eighty-one".