65405521 has 2 divisors, whose sum is σ = 65405522. Its totient is φ = 65405520.

The previous prime is 65405519. The next prime is 65405531. The reversal of 65405521 is 12550456.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 56791296 + 8614225 = 7536^2 + 2935^2 .

It is a cyclic number.

It is not a de Polignac number, because 65405521 - 2¹ = 65405519 is a prime.

Together with 65405519, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 65405521.

It is not a weakly prime, because it can be changed into another prime (65405531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32702760 + 32702761.

It is an arithmetic number, because the mean of its divisors is an integer number (32702761).

Almost surely, 2^65405521 is an apocalyptic number.

It is an amenable number.

65405521 is a deficient number, since it is larger than the sum of its proper divisors (1).

65405521 is an equidigital number, since it uses as much as digits as its factorization.

65405521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6000, while the sum is 28.

The square root of 65405521 is about 8087.3679896490. The cubic root of 65405521 is about 402.9069910784.

Adding to 65405521 its reverse (12550456), we get a palindrome (77955977).

The spelling of 65405521 in words is "sixty-five million, four hundred five thousand, five hundred twenty-one".