669743729 has 2 divisors, whose sum is σ = 669743730. Its totient is φ = 669743728.

The previous prime is 669743717. The next prime is 669743741. The reversal of 669743729 is 927347966.

It is a balanced prime because it is at equal distance from previous prime (669743717) and next prime (669743741).

It can be written as a sum of positive squares in only one way, i.e., 664453729 + 5290000 = 25777^2 + 2300^2 .

It is a cyclic number.

It is not a de Polignac number, because 669743729 - 2²⁴ = 652966513 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (669743759) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334871864 + 334871865.

It is an arithmetic number, because the mean of its divisors is an integer number (334871865).

Almost surely, 2^669743729 is an apocalyptic number.

It is an amenable number.

669743729 is a deficient number, since it is larger than the sum of its proper divisors (1).

669743729 is an equidigital number, since it uses as much as digits as its factorization.

669743729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3429216, while the sum is 53.

The square root of 669743729 is about 25879.4074313922. The cubic root of 669743729 is about 874.9224329608.

The spelling of 669743729 in words is "six hundred sixty-nine million, seven hundred forty-three thousand, seven hundred twenty-nine".