729725321 has 4 divisors (see below), whose sum is σ = 785858052. Its totient is φ = 673592592.

The previous prime is 729725317. The next prime is 729725369. The reversal of 729725321 is 123527927.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 123527927 = 2593 ⋅47639.

It can be written as a sum of positive squares in 2 ways, for example, as 180526096 + 549199225 = 13436^2 + 23435^2 .

It is a cyclic number.

It is not a de Polignac number, because 729725321 - 2² = 729725317 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (729725921) 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, 28066346 + ... + 28066371.

It is an arithmetic number, because the mean of its divisors is an integer number (196464513).

Almost surely, 2^729725321 is an apocalyptic number.

It is an amenable number.

729725321 is a deficient number, since it is larger than the sum of its proper divisors (56132731).

729725321 is a wasteful number, since it uses less digits than its factorization.

729725321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56132730.

The product of its digits is 52920, while the sum is 38.

The square root of 729725321 is about 27013.4285310103. The cubic root of 729725321 is about 900.2983870697.

The spelling of 729725321 in words is "seven hundred twenty-nine million, seven hundred twenty-five thousand, three hundred twenty-one".