866511756740741 has 2 divisors, whose sum is σ = 866511756740742. Its totient is φ = 866511756740740.

The previous prime is 866511756740719. The next prime is 866511756740779. The reversal of 866511756740741 is 147047657115668.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 508611422332225 + 357900334408516 = 22552415^2 + 18918254^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-866511756740741 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 (866511756740341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433255878370370 + 433255878370371.

It is an arithmetic number, because the mean of its divisors is an integer number (433255878370371).

Almost surely, 2^{866511756740741} is an apocalyptic number.

It is an amenable number.

866511756740741 is a deficient number, since it is larger than the sum of its proper divisors (1).

866511756740741 is an equidigital number, since it uses as much as digits as its factorization.

866511756740741 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 237081600, while the sum is 68.

The spelling of 866511756740741 in words is "eight hundred sixty-six trillion, five hundred eleven billion, seven hundred fifty-six million, seven hundred forty thousand, seven hundred forty-one".