28206729 has 12 divisors (see below), whose sum is σ = 41737332. Its totient is φ = 18345600.

The previous prime is 28206707. The next prime is 28206749. The reversal of 28206729 is 92760282.

It can be written as a sum of positive squares in 2 ways, for example, as 360000 + 27846729 = 600^2 + 5277^2 .

It is not a de Polignac number, because 28206729 - 2¹¹ = 28204681 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28206693 and 28206702.

It is not an unprimeable number, because it can be changed into a prime (28206749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 37852 + ... + 38589.

It is an arithmetic number, because the mean of its divisors is an integer number (3478111).

Almost surely, 2^28206729 is an apocalyptic number.

It is an amenable number.

28206729 is a deficient number, since it is larger than the sum of its proper divisors (13530603).

28206729 is a wasteful number, since it uses less digits than its factorization.

28206729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76488 (or 76485 counting only the distinct ones).

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

The square root of 28206729 is about 5311.0007531538. Note that the first 3 decimals coincide. The cubic root of 28206729 is about 304.4043881101.

The spelling of 28206729 in words is "twenty-eight million, two hundred six thousand, seven hundred twenty-nine".