65641 has 4 divisors (see below), whose sum is σ = 67284. Its totient is φ = 64000.

The previous prime is 65633. The next prime is 65647. The reversal of 65641 is 14656.

65641 is nontrivially palindromic in base 11.

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 38416 + 27225 = 196^2 + 165^2 .

It is a 3-Lehmer number, since φ(65641) divides (65641-1)³.

It is a cyclic number.

It is not a de Polignac number, because 65641 - 2³ = 65633 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65647) by changing a digit.

It is a nontrivial repunit in base 40.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 760 + ... + 841.

It is an arithmetic number, because the mean of its divisors is an integer number (16821).

2⁶⁵⁶⁴¹ is an apocalyptic number.

It is an amenable number.

65641 is a deficient number, since it is larger than the sum of its proper divisors (1643).

65641 is a wasteful number, since it uses less digits than its factorization.

65641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1642.

The product of its digits is 720, while the sum is 22.

The square root of 65641 is about 256.2049960481. The cubic root of 65641 is about 40.3389939615.

It can be divided in two parts, 656 and 41, that multiplied together give a square (26896 = 164²).

The spelling of 65641 in words is "sixty-five thousand, six hundred forty-one".