66056261 has 2 divisors, whose sum is σ = 66056262. Its totient is φ = 66056260.

The previous prime is 66056233. The next prime is 66056279. The reversal of 66056261 is 16265066.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65044225 + 1012036 = 8065^2 + 1006^2 .

It is a cyclic number.

It is not a de Polignac number, because 66056261 - 2¹⁸ = 65794117 is a prime.

It is a Sophie Germain 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 (66056231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33028130 + 33028131.

It is an arithmetic number, because the mean of its divisors is an integer number (33028131).

Almost surely, 2^66056261 is an apocalyptic number.

It is an amenable number.

66056261 is a deficient number, since it is larger than the sum of its proper divisors (1).

66056261 is an equidigital number, since it uses as much as digits as its factorization.

66056261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 66056261 is about 8127.5002922178. The cubic root of 66056261 is about 404.2387998555.

The spelling of 66056261 in words is "sixty-six million, fifty-six thousand, two hundred sixty-one".