28239729 has 24 divisors (see below), whose sum is σ = 45220608. Its totient is φ = 15613920.

The previous prime is 28239727. The next prime is 28239779. The reversal of 28239729 is 92793282.

It is not a de Polignac number, because 28239729 - 2¹ = 28239727 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28239727) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1459 + ... + 7655.

It is an arithmetic number, because the mean of its divisors is an integer number (1884192).

Almost surely, 2^28239729 is an apocalyptic number.

It is an amenable number.

28239729 is a deficient number, since it is larger than the sum of its proper divisors (16980879).

28239729 is a wasteful number, since it uses less digits than its factorization.

28239729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6245 (or 6238 counting only the distinct ones).

The product of its digits is 108864, while the sum is 42.

The square root of 28239729 is about 5314.1066041245. The cubic root of 28239729 is about 304.5230528194.

The spelling of 28239729 in words is "twenty-eight million, two hundred thirty-nine thousand, seven hundred twenty-nine".