65491809 has 8 divisors (see below), whose sum is σ = 90139392. Its totient is φ = 42252720.

The previous prime is 65491771. The next prime is 65491817. The reversal of 65491809 is 90819456.

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

It is not a de Polignac number, because 65491809 - 2⁷ = 65491681 is a prime.

It is not an unprimeable number, because it can be changed into a prime (65491819) 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, 352014 + ... + 352199.

It is an arithmetic number, because the mean of its divisors is an integer number (11267424).

Almost surely, 2^65491809 is an apocalyptic number.

It is an amenable number.

65491809 is a deficient number, since it is larger than the sum of its proper divisors (24647583).

65491809 is a wasteful number, since it uses less digits than its factorization.

65491809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 704247.

The product of its (nonzero) digits is 77760, while the sum is 42.

The square root of 65491809 is about 8092.7009706278. The cubic root of 65491809 is about 403.0840951946.

The spelling of 65491809 in words is "sixty-five million, four hundred ninety-one thousand, eight hundred nine".