646906729 has 16 divisors (see below), whose sum is σ = 808068096. Its totient is φ = 505036800.

The previous prime is 646906709. The next prime is 646906759. The reversal of 646906729 is 927609646.

It is a cyclic number.

It is not a de Polignac number, because 646906729 - 2¹⁹ = 646382441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646906709) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 83992 + ... + 91369.

It is an arithmetic number, because the mean of its divisors is an integer number (50504256).

Almost surely, 2^646906729 is an apocalyptic number.

It is an amenable number.

646906729 is a deficient number, since it is larger than the sum of its proper divisors (161161367).

646906729 is a wasteful number, since it uses less digits than its factorization.

646906729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175416.

The product of its (nonzero) digits is 979776, while the sum is 49.

The square root of 646906729 is about 25434.3611871814. The cubic root of 646906729 is about 864.8628109470.

The spelling of 646906729 in words is "six hundred forty-six million, nine hundred six thousand, seven hundred twenty-nine".