666629 has 8 divisors (see below), whose sum is σ = 702240. Its totient is φ = 632016.

The previous prime is 666607. The next prime is 666637. The reversal of 666629 is 926666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 666629 - 2¹⁶ = 601093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1382 + ... + 1800.

It is an arithmetic number, because the mean of its divisors is an integer number (87780).

2⁶⁶⁶⁶²⁹ is an apocalyptic number.

It is an amenable number.

666629 is a deficient number, since it is larger than the sum of its proper divisors (35611).

666629 is a wasteful number, since it uses less digits than its factorization.

666629 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 499.

The product of its digits is 23328, while the sum is 35.

The square root of 666629 is about 816.4735145735. The cubic root of 666629 is about 87.3564011994.

The spelling of 666629 in words is "six hundred sixty-six thousand, six hundred twenty-nine".