66205533625261 has 2 divisors, whose sum is σ = 66205533625262. Its totient is φ = 66205533625260.

The previous prime is 66205533625247. The next prime is 66205533625267. The reversal of 66205533625261 is 16252633550266.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51638869068361 + 14566664556900 = 7186019^2 + 3816630^2 .

It is a cyclic number.

It is not a de Polignac number, because 66205533625261 - 2¹¹ = 66205533623213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66205533625199 and 66205533625208.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66205533625267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33102766812630 + 33102766812631.

It is an arithmetic number, because the mean of its divisors is an integer number (33102766812631).

Almost surely, 2^{66205533625261} is an apocalyptic number.

It is an amenable number.

66205533625261 is a deficient number, since it is larger than the sum of its proper divisors (1).

66205533625261 is an equidigital number, since it uses as much as digits as its factorization.

66205533625261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11664000, while the sum is 52.

The spelling of 66205533625261 in words is "sixty-six trillion, two hundred five billion, five hundred thirty-three million, six hundred twenty-five thousand, two hundred sixty-one".