65809081 has 4 divisors (see below), whose sum is σ = 70871332. Its totient is φ = 60746832.

The previous prime is 65809067. The next prime is 65809109. The reversal of 65809081 is 18090856.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19501056 + 46308025 = 4416^2 + 6805^2 .

It is a cyclic number.

It is not a de Polignac number, because 65809081 - 2¹⁵ = 65776313 is a prime.

It is a super-2 number, since 2×65809081² = 8661670284129122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 65809081.

It is not an unprimeable number, because it can be changed into a prime (65809021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2531106 + ... + 2531131.

It is an arithmetic number, because the mean of its divisors is an integer number (17717833).

Almost surely, 2^65809081 is an apocalyptic number.

It is an amenable number.

65809081 is a deficient number, since it is larger than the sum of its proper divisors (5062251).

65809081 is a wasteful number, since it uses less digits than its factorization.

65809081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5062250.

The product of its (nonzero) digits is 17280, while the sum is 37.

The square root of 65809081 is about 8112.2796426159. The cubic root of 65809081 is about 403.7339542550.

The spelling of 65809081 in words is "sixty-five million, eight hundred nine thousand, eighty-one".