729134221 has 4 divisors (see below), whose sum is σ = 729488700. Its totient is φ = 728779744.

The previous prime is 729134207. The next prime is 729134227. The reversal of 729134221 is 122431927.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 267486025 + 461648196 = 16355^2 + 21486^2 .

It is a cyclic number.

It is not a de Polignac number, because 729134221 - 2¹⁵ = 729101453 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 (729134227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 174136 + ... + 178273.

It is an arithmetic number, because the mean of its divisors is an integer number (182372175).

Almost surely, 2^729134221 is an apocalyptic number.

It is an amenable number.

729134221 is a deficient number, since it is larger than the sum of its proper divisors (354479).

729134221 is a wasteful number, since it uses less digits than its factorization.

729134221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 354478.

The product of its digits is 6048, while the sum is 31.

The square root of 729134221 is about 27002.4854596757. The cubic root of 729134221 is about 900.0552315899.

The spelling of 729134221 in words is "seven hundred twenty-nine million, one hundred thirty-four thousand, two hundred twenty-one".