66261142737791 has 2 divisors, whose sum is σ = 66261142737792. Its totient is φ = 66261142737790.

The previous prime is 66261142737749. The next prime is 66261142737799. The reversal of 66261142737791 is 19773724116266.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66261142737791 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66261142737799) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33130571368895 + 33130571368896.

It is an arithmetic number, because the mean of its divisors is an integer number (33130571368896).

Almost surely, 2^{66261142737791} is an apocalyptic number.

66261142737791 is a deficient number, since it is larger than the sum of its proper divisors (1).

66261142737791 is an equidigital number, since it uses as much as digits as its factorization.

66261142737791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32006016, while the sum is 62.

The spelling of 66261142737791 in words is "sixty-six trillion, two hundred sixty-one billion, one hundred forty-two million, seven hundred thirty-seven thousand, seven hundred ninety-one".