491544913897 has 2 divisors, whose sum is σ = 491544913898. Its totient is φ = 491544913896.

The previous prime is 491544913829. The next prime is 491544913921. The reversal of 491544913897 is 798319445194.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 479661515776 + 11883398121 = 692576^2 + 109011^2 .

It is a cyclic number.

It is not a de Polignac number, because 491544913897 - 2¹⁵ = 491544881129 is a prime.

It is not a weakly prime, because it can be changed into another prime (491544913297) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245772456948 + 245772456949.

It is an arithmetic number, because the mean of its divisors is an integer number (245772456949).

Almost surely, 2^491544913897 is an apocalyptic number.

It is an amenable number.

491544913897 is a deficient number, since it is larger than the sum of its proper divisors (1).

491544913897 is an equidigital number, since it uses as much as digits as its factorization.

491544913897 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 39191040, while the sum is 64.

The spelling of 491544913897 in words is "four hundred ninety-one billion, five hundred forty-four million, nine hundred thirteen thousand, eight hundred ninety-seven".