665126729 has 2 divisors, whose sum is σ = 665126730. Its totient is φ = 665126728.

The previous prime is 665126677. The next prime is 665126743. The reversal of 665126729 is 927621566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 540469504 + 124657225 = 23248^2 + 11165^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665126729 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 665126729.

It is not a weakly prime, because it can be changed into another prime (665126779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332563364 + 332563365.

It is an arithmetic number, because the mean of its divisors is an integer number (332563365).

Almost surely, 2^665126729 is an apocalyptic number.

It is an amenable number.

665126729 is a deficient number, since it is larger than the sum of its proper divisors (1).

665126729 is an equidigital number, since it uses as much as digits as its factorization.

665126729 is an evil number, because the sum of its binary digits is even.

The product of its digits is 272160, while the sum is 44.

The square root of 665126729 is about 25790.0509693176. The cubic root of 665126729 is about 872.9073164355.

The spelling of 665126729 in words is "six hundred sixty-five million, one hundred twenty-six thousand, seven hundred twenty-nine".