66706765651 has 2 divisors, whose sum is σ = 66706765652. Its totient is φ = 66706765650.

The previous prime is 66706765639. The next prime is 66706765663. The reversal of 66706765651 is 15656760766.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (66706765639) and next prime (66706765663).

It is a cyclic number.

It is not a de Polignac number, because 66706765651 - 2¹¹ = 66706763603 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66706765592 and 66706765601.

It is not a weakly prime, because it can be changed into another prime (66706765351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33353382825 + 33353382826.

It is an arithmetic number, because the mean of its divisors is an integer number (33353382826).

Almost surely, 2^66706765651 is an apocalyptic number.

66706765651 is a deficient number, since it is larger than the sum of its proper divisors (1).

66706765651 is an equidigital number, since it uses as much as digits as its factorization.

66706765651 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9525600, while the sum is 55.

The spelling of 66706765651 in words is "sixty-six billion, seven hundred six million, seven hundred sixty-five thousand, six hundred fifty-one".