28072729 has 8 divisors (see below), whose sum is σ = 30101760. Its totient is φ = 26085696.

The previous prime is 28072727. The next prime is 28072757. The reversal of 28072729 is 92727082.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28072729 - 2¹ = 28072727 is a prime.

It is a super-2 number, since 2×28072729² = 1576156227014882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28072721) 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 7 ways as a sum of consecutive naturals, for example, 9109 + ... + 11794.

It is an arithmetic number, because the mean of its divisors is an integer number (3762720).

Almost surely, 2^28072729 is an apocalyptic number.

It is an amenable number.

28072729 is a deficient number, since it is larger than the sum of its proper divisors (2029031).

28072729 is a wasteful number, since it uses less digits than its factorization.

28072729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20999.

The product of its (nonzero) digits is 28224, while the sum is 37.

The square root of 28072729 is about 5298.3704098524. The cubic root of 28072729 is about 303.9215842587.

The spelling of 28072729 in words is "twenty-eight million, seventy-two thousand, seven hundred twenty-nine".