66124556081 has 2 divisors, whose sum is σ = 66124556082. Its totient is φ = 66124556080.

The previous prime is 66124556011. The next prime is 66124556087. The reversal of 66124556081 is 18065542166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60610008481 + 5514547600 = 246191^2 + 74260^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66124556081 is a prime.

It is a super-2 number, since 2×66124556081² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66124556087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33062278040 + 33062278041.

It is an arithmetic number, because the mean of its divisors is an integer number (33062278041).

Almost surely, 2^66124556081 is an apocalyptic number.

It is an amenable number.

66124556081 is a deficient number, since it is larger than the sum of its proper divisors (1).

66124556081 is an equidigital number, since it uses as much as digits as its factorization.

66124556081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 345600, while the sum is 44.

The spelling of 66124556081 in words is "sixty-six billion, one hundred twenty-four million, five hundred fifty-six thousand, eighty-one".