65783281 has 4 divisors (see below), whose sum is σ = 68051700. Its totient is φ = 63514864.

The previous prime is 65783257. The next prime is 65783287. The reversal of 65783281 is 18238756.

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 54893281 + 10890000 = 7409^2 + 3300^2 .

It is a cyclic number.

It is not a de Polignac number, because 65783281 - 2¹³ = 65775089 is a prime.

It is a super-2 number, since 2×65783281² = 8654880118249922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65783287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1134166 + ... + 1134223.

It is an arithmetic number, because the mean of its divisors is an integer number (17012925).

Almost surely, 2^65783281 is an apocalyptic number.

It is an amenable number.

65783281 is a deficient number, since it is larger than the sum of its proper divisors (2268419).

65783281 is a wasteful number, since it uses less digits than its factorization.

65783281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2268418.

The product of its digits is 80640, while the sum is 40.

The square root of 65783281 is about 8110.6893048618. The cubic root of 65783281 is about 403.6811869805.

It can be divided in two parts, 657 and 83281, that added together give a palindrome (83938).

The spelling of 65783281 in words is "sixty-five million, seven hundred eighty-three thousand, two hundred eighty-one".