491899999 has 8 divisors (see below), whose sum is σ = 499207968. Its totient is φ = 484602720.

The previous prime is 491899957. The next prime is 491900029. The reversal of 491899999 is 999998194.

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 491899999 - 2⁷ = 491899871 is a prime.

It is a Duffinian number.

491899999 is a modest number, since divided by 99999 gives 4918 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491399999) 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, 174469 + ... + 177265.

It is an arithmetic number, because the mean of its divisors is an integer number (62400996).

Almost surely, 2^491899999 is an apocalyptic number.

491899999 is a deficient number, since it is larger than the sum of its proper divisors (7307969).

491899999 is a wasteful number, since it uses less digits than its factorization.

491899999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5345.

The product of its digits is 17006112, while the sum is 67.

The square root of 491899999 is about 22178.8187016351. The cubic root of 491899999 is about 789.3911877261.

The spelling of 491899999 in words is "four hundred ninety-one million, eight hundred ninety-nine thousand, nine hundred ninety-nine".