66616129 has 2 divisors, whose sum is σ = 66616130. Its totient is φ = 66616128.

The previous prime is 66616127. The next prime is 66616139. The reversal of 66616129 is 92161666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 44195904 + 22420225 = 6648^2 + 4735^2 .

It is a cyclic number.

It is not a de Polignac number, because 66616129 - 2¹ = 66616127 is a prime.

Together with 66616127, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66616127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33308064 + 33308065.

It is an arithmetic number, because the mean of its divisors is an integer number (33308065).

Almost surely, 2^66616129 is an apocalyptic number.

It is an amenable number.

66616129 is a deficient number, since it is larger than the sum of its proper divisors (1).

66616129 is an equidigital number, since it uses as much as digits as its factorization.

66616129 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23328, while the sum is 37.

The square root of 66616129 is about 8161.8704351392. The cubic root of 66616129 is about 405.3776470378.

The spelling of 66616129 in words is "sixty-six million, six hundred sixteen thousand, one hundred twenty-nine".