66520211 has 2 divisors, whose sum is σ = 66520212. Its totient is φ = 66520210.

The previous prime is 66520177. The next prime is 66520217. The reversal of 66520211 is 11202566.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66520211 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (66520217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33260105 + 33260106.

It is an arithmetic number, because the mean of its divisors is an integer number (33260106).

Almost surely, 2^66520211 is an apocalyptic number.

66520211 is a deficient number, since it is larger than the sum of its proper divisors (1).

66520211 is an equidigital number, since it uses as much as digits as its factorization.

66520211 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 66520211 is about 8155.9923369263. The cubic root of 66520211 is about 405.1829910252.

Adding to 66520211 its reverse (11202566), we get a palindrome (77722777).

The spelling of 66520211 in words is "sixty-six million, five hundred twenty thousand, two hundred eleven".