66520313 has 2 divisors, whose sum is σ = 66520314. Its totient is φ = 66520312.

The previous prime is 66520283. The next prime is 66520319. The reversal of 66520313 is 31302566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60964864 + 5555449 = 7808^2 + 2357^2 .

It is a cyclic number.

It is not a de Polignac number, because 66520313 - 2⁶ = 66520249 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66520319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33260156 + 33260157.

It is an arithmetic number, because the mean of its divisors is an integer number (33260157).

Almost surely, 2^66520313 is an apocalyptic number.

It is an amenable number.

66520313 is a deficient number, since it is larger than the sum of its proper divisors (1).

66520313 is an equidigital number, since it uses as much as digits as its factorization.

66520313 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 26.

The square root of 66520313 is about 8155.9985899950. The cubic root of 66520313 is about 405.1831981234.

Adding to 66520313 its reverse (31302566), we get a palindrome (97822879).

The spelling of 66520313 in words is "sixty-six million, five hundred twenty thousand, three hundred thirteen".