666906729 has 4 divisors (see below), whose sum is σ = 889208976. Its totient is φ = 444604484.

The previous prime is 666906701. The next prime is 666906733. The reversal of 666906729 is 927609666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 666906729 - 2⁷ = 666906601 is a prime.

It is not an unprimeable number, because it can be changed into a prime (666906329) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111151119 + ... + 111151124.

It is an arithmetic number, because the mean of its divisors is an integer number (222302244).

Almost surely, 2^666906729 is an apocalyptic number.

It is an amenable number.

666906729 is a deficient number, since it is larger than the sum of its proper divisors (222302247).

666906729 is a wasteful number, since it uses less digits than its factorization.

666906729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222302246.

The product of its (nonzero) digits is 1469664, while the sum is 51.

The square root of 666906729 is about 25824.5373433872. The cubic root of 666906729 is about 873.6853090351.

The spelling of 666906729 in words is "six hundred sixty-six million, nine hundred six thousand, seven hundred twenty-nine".