28057729 has 16 divisors (see below), whose sum is σ = 33230848. Its totient is φ = 23188032.

The previous prime is 28057721. The next prime is 28057739. The reversal of 28057729 is 92775082.

It is not a de Polignac number, because 28057729 - 2³ = 28057721 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28057691 and 28057700.

It is not an unprimeable number, because it can be changed into a prime (28057721) 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, 32467 + ... + 33319.

It is an arithmetic number, because the mean of its divisors is an integer number (2076928).

Almost surely, 2^28057729 is an apocalyptic number.

It is an amenable number.

28057729 is a deficient number, since it is larger than the sum of its proper divisors (5173119).

28057729 is a wasteful number, since it uses less digits than its factorization.

28057729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1024.

The product of its (nonzero) digits is 70560, while the sum is 40.

The square root of 28057729 is about 5296.9546911409. The cubic root of 28057729 is about 303.8674435068.

The spelling of 28057729 in words is "twenty-eight million, fifty-seven thousand, seven hundred twenty-nine".