66115861811 has 2 divisors, whose sum is σ = 66115861812. Its totient is φ = 66115861810.

The previous prime is 66115861759. The next prime is 66115861829. The reversal of 66115861811 is 11816851166.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66115861811 is a prime.

It is a super-2 number, since 2×66115861811² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66115861411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33057930905 + 33057930906.

It is an arithmetic number, because the mean of its divisors is an integer number (33057930906).

Almost surely, 2^66115861811 is an apocalyptic number.

66115861811 is a deficient number, since it is larger than the sum of its proper divisors (1).

66115861811 is an equidigital number, since it uses as much as digits as its factorization.

66115861811 is an evil number, because the sum of its binary digits is even.

The product of its digits is 69120, while the sum is 44.

The spelling of 66115861811 in words is "sixty-six billion, one hundred fifteen million, eight hundred sixty-one thousand, eight hundred eleven".