65921 has 2 divisors, whose sum is σ = 65922. Its totient is φ = 65920.

The previous prime is 65899. The next prime is 65927. The reversal of 65921 is 12956.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 40000 + 25921 = 200^2 + 161^2 .

It is a cyclic number.

It is not a de Polignac number, because 65921 - 2¹⁴ = 49537 is a prime.

It is a plaindrome in base 11.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 65921.

It is not a weakly prime, because it can be changed into another prime (65927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32960 + 32961.

It is an arithmetic number, because the mean of its divisors is an integer number (32961).

2⁶⁵⁹²¹ is an apocalyptic number.

It is an amenable number.

65921 is a deficient number, since it is larger than the sum of its proper divisors (1).

65921 is an equidigital number, since it uses as much as digits as its factorization.

65921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 540, while the sum is 23.

The square root of 65921 is about 256.7508519947. The cubic root of 65921 is about 40.3962696291.

The spelling of 65921 in words is "sixty-five thousand, nine hundred twenty-one".