491689985 has 8 divisors (see below), whose sum is σ = 590391936. Its totient is φ = 393109360.

The previous prime is 491689969. The next prime is 491689987. The reversal of 491689985 is 589986194.

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

It is not a de Polignac number, because 491689985 - 2⁴ = 491689969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (491689987) 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, 21161 + ... + 37830.

It is an arithmetic number, because the mean of its divisors is an integer number (73798992).

Almost surely, 2^491689985 is an apocalyptic number.

It is an amenable number.

491689985 is a deficient number, since it is larger than the sum of its proper divisors (98701951).

491689985 is a wasteful number, since it uses less digits than its factorization.

491689985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60663.

The product of its digits is 5598720, while the sum is 59.

The square root of 491689985 is about 22174.0836338280. The cubic root of 491689985 is about 789.2788296585.

The spelling of 491689985 in words is "four hundred ninety-one million, six hundred eighty-nine thousand, nine hundred eighty-five".