666729 has 24 divisors (see below), whose sum is σ = 1160640. Its totient is φ = 360288.

The previous prime is 666727. The next prime is 666733. The reversal of 666729 is 927666.

It is not a de Polignac number, because 666729 - 2¹ = 666727 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 666693 and 666702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666727) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 919 + ... + 1475.

It is an arithmetic number, because the mean of its divisors is an integer number (48360).

2⁶⁶⁶⁷²⁹ is an apocalyptic number.

It is an amenable number.

666729 is a deficient number, since it is larger than the sum of its proper divisors (493911).

666729 is a wasteful number, since it uses less digits than its factorization.

666729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 589 (or 586 counting only the distinct ones).

The product of its digits is 27216, while the sum is 36.

The square root of 666729 is about 816.5347512507. The cubic root of 666729 is about 87.3607690479.

The spelling of 666729 in words is "six hundred sixty-six thousand, seven hundred twenty-nine".