729405 has 20 divisors (see below), whose sum is σ = 1308252. Its totient is φ = 388800.

The previous prime is 729403. The next prime is 729413. The reversal of 729405 is 504927.

729405 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 171396 + 558009 = 414^2 + 747^2 .

It is not a de Polignac number, because 729405 - 2¹ = 729403 is a prime.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (729403) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 496 + ... + 1305.

2⁷²⁹⁴⁰⁵ is an apocalyptic number.

It is an amenable number.

729405 is a deficient number, since it is larger than the sum of its proper divisors (578847).

729405 is a wasteful number, since it uses less digits than its factorization.

729405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1818 (or 1809 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 27.

The square root of 729405 is about 854.0521061387. The cubic root of 729405 is about 90.0166635812.

The spelling of 729405 in words is "seven hundred twenty-nine thousand, four hundred five".