65523509 has 2 divisors, whose sum is σ = 65523510. Its totient is φ = 65523508.

The previous prime is 65523503. The next prime is 65523511. The reversal of 65523509 is 90532556.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38254225 + 27269284 = 6185^2 + 5222^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-65523509 is a prime.

It is a Sophie Germain prime.

Together with 65523511, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65523503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32761754 + 32761755.

It is an arithmetic number, because the mean of its divisors is an integer number (32761755).

Almost surely, 2^65523509 is an apocalyptic number.

It is an amenable number.

65523509 is a deficient number, since it is larger than the sum of its proper divisors (1).

65523509 is an equidigital number, since it uses as much as digits as its factorization.

65523509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40500, while the sum is 35.

The square root of 65523509 is about 8094.6592886915. The cubic root of 65523509 is about 403.1491196353.

The spelling of 65523509 in words is "sixty-five million, five hundred twenty-three thousand, five hundred nine".