66796799989 has 2 divisors, whose sum is σ = 66796799990. Its totient is φ = 66796799988.

The previous prime is 66796799987. The next prime is 66796800019. The reversal of 66796799989 is 98999769766.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 58801400100 + 7995399889 = 242490^2 + 89417^2 .

It is a cyclic number.

It is not a de Polignac number, because 66796799989 - 2¹ = 66796799987 is a prime.

Together with 66796799987, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66796799981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33398399994 + 33398399995.

It is an arithmetic number, because the mean of its divisors is an integer number (33398399995).

Almost surely, 2^66796799989 is an apocalyptic number.

It is an amenable number.

66796799989 is a deficient number, since it is larger than the sum of its proper divisors (1).

66796799989 is an equidigital number, since it uses as much as digits as its factorization.

66796799989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4999796928, while the sum is 85.

The spelling of 66796799989 in words is "sixty-six billion, seven hundred ninety-six million, seven hundred ninety-nine thousand, nine hundred eighty-nine".