66558835481 has 2 divisors, whose sum is σ = 66558835482. Its totient is φ = 66558835480.

The previous prime is 66558835463. The next prime is 66558835507. The reversal of 66558835481 is 18453885566.

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., 64617640000 + 1941195481 = 254200^2 + 44059^2 .

It is a cyclic number.

It is not a de Polignac number, because 66558835481 - 2¹⁰ = 66558834457 is a prime.

It is a super-2 number, since 2×66558835481² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 66558835481.

It is not a weakly prime, because it can be changed into another prime (66558835181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33279417740 + 33279417741.

It is an arithmetic number, because the mean of its divisors is an integer number (33279417741).

Almost surely, 2^66558835481 is an apocalyptic number.

It is an amenable number.

66558835481 is a deficient number, since it is larger than the sum of its proper divisors (1).

66558835481 is an equidigital number, since it uses as much as digits as its factorization.

66558835481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27648000, while the sum is 59.

The spelling of 66558835481 in words is "sixty-six billion, five hundred fifty-eight million, eight hundred thirty-five thousand, four hundred eighty-one".