866191129 has 2 divisors, whose sum is σ = 866191130. Its totient is φ = 866191128.

The previous prime is 866191103. The next prime is 866191147. The reversal of 866191129 is 921191668.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 477509904 + 388681225 = 21852^2 + 19715^2 .

It is a cyclic number.

It is not a de Polignac number, because 866191129 - 2⁹ = 866190617 is a prime.

It is not a weakly prime, because it can be changed into another prime (866191159) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433095564 + 433095565.

It is an arithmetic number, because the mean of its divisors is an integer number (433095565).

Almost surely, 2^866191129 is an apocalyptic number.

It is an amenable number.

866191129 is a deficient number, since it is larger than the sum of its proper divisors (1).

866191129 is an equidigital number, since it uses as much as digits as its factorization.

866191129 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 46656, while the sum is 43.

The square root of 866191129 is about 29431.1251738699. The cubic root of 866191129 is about 953.2450905195.

The spelling of 866191129 in words is "eight hundred sixty-six million, one hundred ninety-one thousand, one hundred twenty-nine".