66494785961 has 2 divisors, whose sum is σ = 66494785962. Its totient is φ = 66494785960.

The previous prime is 66494785943. The next prime is 66494786011. The reversal of 66494785961 is 16958749466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 45275328400 + 21219457561 = 212780^2 + 145669^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66494785961 is a prime.

It is not a weakly prime, because it can be changed into another prime (66494785901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33247392980 + 33247392981.

It is an arithmetic number, because the mean of its divisors is an integer number (33247392981).

Almost surely, 2^66494785961 is an apocalyptic number.

It is an amenable number.

66494785961 is a deficient number, since it is larger than the sum of its proper divisors (1).

66494785961 is an equidigital number, since it uses as much as digits as its factorization.

66494785961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 78382080, while the sum is 65.

The spelling of 66494785961 in words is "sixty-six billion, four hundred ninety-four million, seven hundred eighty-five thousand, nine hundred sixty-one".