65641861 has 8 divisors (see below), whose sum is σ = 68002200. Its totient is φ = 63317760.

The previous prime is 65641847. The next prime is 65641867. The reversal of 65641861 is 16814656.

It can be written as a sum of positive squares in 4 ways, for example, as 516961 + 65124900 = 719^2 + 8070^2 .

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 65641861 - 2²¹ = 63544709 is a prime.

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 65641861.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65641867) 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, 5346 + ... + 12643.

It is an arithmetic number, because the mean of its divisors is an integer number (8500275).

Almost surely, 2^65641861 is an apocalyptic number.

It is an amenable number.

65641861 is a deficient number, since it is larger than the sum of its proper divisors (2360339).

65641861 is a wasteful number, since it uses less digits than its factorization.

65641861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18119.

The product of its digits is 34560, while the sum is 37.

The square root of 65641861 is about 8101.9664896863. The cubic root of 65641861 is about 403.3917033358.

The spelling of 65641861 in words is "sixty-five million, six hundred forty-one thousand, eight hundred sixty-one".