999729 has 16 divisors (see below), whose sum is σ = 1507840. Its totient is φ = 654480.

The previous prime is 999727. The next prime is 999749. The reversal of 999729 is 927999.

It is not a de Polignac number, because 999729 - 2¹ = 999727 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (999721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1344 + ... + 1950.

It is an arithmetic number, because the mean of its divisors is an integer number (94240).

2⁹⁹⁹⁷²⁹ is an apocalyptic number.

It is an amenable number.

999729 is a deficient number, since it is larger than the sum of its proper divisors (508111).

999729 is a wasteful number, since it uses less digits than its factorization.

999729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 677 (or 671 counting only the distinct ones).

The product of its digits is 91854, while the sum is 45.

The square root of 999729 is about 999.8644908186. The cubic root of 999729 is about 99.9909658505.

It can be divided in two parts, 999 and 729, that added together give a cube (1728 = 12³).

The spelling of 999729 in words is "nine hundred ninety-nine thousand, seven hundred twenty-nine".