729857217 has 4 divisors (see below), whose sum is σ = 973142960. Its totient is φ = 486571476.

The previous prime is 729857147. The next prime is 729857237. The reversal of 729857217 is 712758927.

It is a happy number.

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 not a de Polignac number, because 729857217 - 2²⁶ = 662748353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (729857237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121642867 + ... + 121642872.

It is an arithmetic number, because the mean of its divisors is an integer number (243285740).

Almost surely, 2^729857217 is an apocalyptic number.

It is an amenable number.

729857217 is a deficient number, since it is larger than the sum of its proper divisors (243285743).

729857217 is a wasteful number, since it uses less digits than its factorization.

729857217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243285742.

The product of its digits is 493920, while the sum is 48.

The square root of 729857217 is about 27015.8697250338. The cubic root of 729857217 is about 900.3526260183.

The spelling of 729857217 in words is "seven hundred twenty-nine million, eight hundred fifty-seven thousand, two hundred seventeen".