28809729 has 32 divisors (see below), whose sum is σ = 46300800. Its totient is φ = 17599680.

The previous prime is 28809727. The next prime is 28809733. The reversal of 28809729 is 92790882.

It is not a de Polignac number, because 28809729 - 2¹ = 28809727 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28809721) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 73867 + ... + 74255.

It is an arithmetic number, because the mean of its divisors is an integer number (1446900).

Almost surely, 2^28809729 is an apocalyptic number.

It is an amenable number.

28809729 is a deficient number, since it is larger than the sum of its proper divisors (17491071).

28809729 is a wasteful number, since it uses less digits than its factorization.

28809729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 622 (or 616 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 28809729 is about 5367.4695155166. The cubic root of 28809729 is about 306.5582849255.

The spelling of 28809729 in words is "twenty-eight million, eight hundred nine thousand, seven hundred twenty-nine".