666122129 has 2 divisors, whose sum is σ = 666122130. Its totient is φ = 666122128.

The previous prime is 666122111. The next prime is 666122167. The reversal of 666122129 is 921221666.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 661878529 + 4243600 = 25727^2 + 2060^2 .

It is a cyclic number.

It is not a de Polignac number, because 666122129 - 2⁸ = 666121873 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (666122189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333061064 + 333061065.

It is an arithmetic number, because the mean of its divisors is an integer number (333061065).

Almost surely, 2^666122129 is an apocalyptic number.

It is an amenable number.

666122129 is a deficient number, since it is larger than the sum of its proper divisors (1).

666122129 is an equidigital number, since it uses as much as digits as its factorization.

666122129 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15552, while the sum is 35.

The square root of 666122129 is about 25809.3418939732. The cubic root of 666122129 is about 873.3425512141.

The spelling of 666122129 in words is "six hundred sixty-six million, one hundred twenty-two thousand, one hundred twenty-nine".