66126058981 has 2 divisors, whose sum is σ = 66126058982. Its totient is φ = 66126058980.

The previous prime is 66126058949. The next prime is 66126059029. The reversal of 66126058981 is 18985062166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66118408225 + 7650756 = 257135^2 + 2766^2 .

It is a cyclic number.

It is not a de Polignac number, because 66126058981 - 2⁵ = 66126058949 is a prime.

It is a super-2 number, since 2×66126058981² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66126058081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33063029490 + 33063029491.

It is an arithmetic number, because the mean of its divisors is an integer number (33063029491).

Almost surely, 2^66126058981 is an apocalyptic number.

It is an amenable number.

66126058981 is a deficient number, since it is larger than the sum of its proper divisors (1).

66126058981 is an equidigital number, since it uses as much as digits as its factorization.

66126058981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1244160, while the sum is 52.

The spelling of 66126058981 in words is "sixty-six billion, one hundred twenty-six million, fifty-eight thousand, nine hundred eighty-one".