66205213 has 2 divisors, whose sum is σ = 66205214. Its totient is φ = 66205212.

The previous prime is 66205211. The next prime is 66205219. The reversal of 66205213 is 31250266.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 63011844 + 3193369 = 7938^2 + 1787^2 .

It is a cyclic number.

It is not a de Polignac number, because 66205213 - 2¹ = 66205211 is a prime.

Together with 66205211, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66205211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33102606 + 33102607.

It is an arithmetic number, because the mean of its divisors is an integer number (33102607).

Almost surely, 2^66205213 is an apocalyptic number.

It is an amenable number.

66205213 is a deficient number, since it is larger than the sum of its proper divisors (1).

66205213 is an equidigital number, since it uses as much as digits as its factorization.

66205213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 66205213 is about 8136.6585893719. The cubic root of 66205213 is about 404.5424146600.

Adding to 66205213 its reverse (31250266), we get a palindrome (97455479).

The spelling of 66205213 in words is "sixty-six million, two hundred five thousand, two hundred thirteen".