66956216801 has 2 divisors, whose sum is σ = 66956216802. Its totient is φ = 66956216800.

The previous prime is 66956216741. The next prime is 66956216861. The reversal of 66956216801 is 10861265966.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (66956216741) and next prime (66956216861).

It can be written as a sum of positive squares in only one way, i.e., 43170866176 + 23785350625 = 207776^2 + 154225^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66956216801 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66956216801.

It is not a weakly prime, because it can be changed into another prime (66956216861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33478108400 + 33478108401.

It is an arithmetic number, because the mean of its divisors is an integer number (33478108401).

Almost surely, 2^66956216801 is an apocalyptic number.

It is an amenable number.

66956216801 is a deficient number, since it is larger than the sum of its proper divisors (1).

66956216801 is an equidigital number, since it uses as much as digits as its factorization.

66956216801 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 933120, while the sum is 50.

The spelling of 66956216801 in words is "sixty-six billion, nine hundred fifty-six million, two hundred sixteen thousand, eight hundred one".