491908889 has 8 divisors (see below), whose sum is σ = 543490560. Its totient is φ = 442843456.

The previous prime is 491908873. The next prime is 491908897. The reversal of 491908889 is 988809194.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 491908889 - 2⁴ = 491908873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (491905889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 628649 + ... + 629430.

It is an arithmetic number, because the mean of its divisors is an integer number (67936320).

Almost surely, 2^491908889 is an apocalyptic number.

It is an amenable number.

491908889 is a deficient number, since it is larger than the sum of its proper divisors (51581671).

491908889 is a wasteful number, since it uses less digits than its factorization.

491908889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1258119.

The product of its (nonzero) digits is 1492992, while the sum is 56.

The square root of 491908889 is about 22179.0191171747. The cubic root of 491908889 is about 789.3959431949.

The spelling of 491908889 in words is "four hundred ninety-one million, nine hundred eight thousand, eight hundred eighty-nine".