491509354849 has 4 divisors (see below), whose sum is σ = 507364495360. Its totient is φ = 475654214340.

The previous prime is 491509354841. The next prime is 491509354937. The reversal of 491509354849 is 948453905194.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 948453905194 = 2 ⋅474226952597.

It is a cyclic number.

It is not a de Polignac number, because 491509354849 - 2³ = 491509354841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (491509354841) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7927570209 + ... + 7927570270.

It is an arithmetic number, because the mean of its divisors is an integer number (126841123840).

Almost surely, 2^491509354849 is an apocalyptic number.

It is an amenable number.

491509354849 is a deficient number, since it is larger than the sum of its proper divisors (15855140511).

491509354849 is a wasteful number, since it uses less digits than its factorization.

491509354849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15855140510.

The product of its (nonzero) digits is 27993600, while the sum is 61.

The spelling of 491509354849 in words is "four hundred ninety-one billion, five hundred nine million, three hundred fifty-four thousand, eight hundred forty-nine".