491720289 has 8 divisors (see below), whose sum is σ = 684132672. Its totient is φ = 313560720.

The previous prime is 491720267. The next prime is 491720293. The reversal of 491720289 is 982027194.

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

It is not a de Polignac number, because 491720289 - 2⁷ = 491720161 is a prime.

It is a super-2 number, since 2×491720289² = 483577685228487042, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 491720289.

It is not an unprimeable number, because it can be changed into a prime (491720239) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3563122 + ... + 3563259.

It is an arithmetic number, because the mean of its divisors is an integer number (85516584).

Almost surely, 2^491720289 is an apocalyptic number.

It is an amenable number.

491720289 is a deficient number, since it is larger than the sum of its proper divisors (192412383).

491720289 is a wasteful number, since it uses less digits than its factorization.

491720289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7126407.

The product of its (nonzero) digits is 72576, while the sum is 42.

The square root of 491720289 is about 22174.7669435329. The cubic root of 491720289 is about 789.2950443568.

The spelling of 491720289 in words is "four hundred ninety-one million, seven hundred twenty thousand, two hundred eighty-nine".