729664 has 28 divisors (see below), whose sum is σ = 1561084. Its totient is φ = 336384.

The previous prime is 729661. The next prime is 729671. The reversal of 729664 is 466927.

It can be written as a sum of positive squares in 2 ways, for example, as 360000 + 369664 = 600^2 + 608^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (729661) 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, 394 + ... + 1270.

It is an arithmetic number, because the mean of its divisors is an integer number (55753).

2⁷²⁹⁶⁶⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 729664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (780542).

729664 is an abundant number, since it is smaller than the sum of its proper divisors (831420).

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

729664 is a wasteful number, since it uses less digits than its factorization.

729664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 902 (or 892 counting only the distinct ones).

The product of its digits is 18144, while the sum is 34.

The square root of 729664 is about 854.2037227734. The cubic root of 729664 is about 90.0273168108.

The spelling of 729664 in words is "seven hundred twenty-nine thousand, six hundred sixty-four".