729684 has 18 divisors (see below), whose sum is σ = 1844570. Its totient is φ = 243216.

The previous prime is 729679. The next prime is 729689. The reversal of 729684 is 486927.

It is an interprime number because it is at equal distance from previous prime (729679) and next prime (729689).

It can be written as a sum of positive squares in only one way, i.e., 685584 + 44100 = 828^2 + 210^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 20269 = 729684 / (7 + 2 + 9 + 6 + 8 + 4).

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (729689) by changing a digit.

729684 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10099 + ... + 10170.

2⁷²⁹⁶⁸⁴ is an apocalyptic number.

It is an amenable number.

729684 is an abundant number, since it is smaller than the sum of its proper divisors (1114886).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

729684 is a wasteful number, since it uses less digits than its factorization.

729684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20279 (or 20274 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 729684 is about 854.2154295024. The cubic root of 729684 is about 90.0281393492.

The spelling of 729684 in words is "seven hundred twenty-nine thousand, six hundred eighty-four".