491086390221 has 96 divisors (see below), whose sum is σ = 871937248000. Its totient is φ = 276017595840.

The previous prime is 491086390219. The next prime is 491086390271. The reversal of 491086390221 is 122093680194.

491086390221 is a `hidden beast` number, since 4 + 9 + 1 + 0 + 8 + 639 + 0 + 2 + 2 + 1 = 666.

It is not a de Polignac number, because 491086390221 - 2¹ = 491086390219 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491086390211) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 5035995 + ... + 5132583.

Almost surely, 2^491086390221 is an apocalyptic number.

It is an amenable number.

491086390221 is a deficient number, since it is larger than the sum of its proper divisors (380850857779).

491086390221 is an frugal number, since it uses more digits than its factorization.

491086390221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96686 (or 96660 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 45.

The spelling of 491086390221 in words is "four hundred ninety-one billion, eighty-six million, three hundred ninety thousand, two hundred twenty-one".