28236939 has 32 divisors (see below), whose sum is σ = 41631744. Its totient is φ = 16964640.

The previous prime is 28236899. The next prime is 28236947. The reversal of 28236939 is 93963282.

It is not a de Polignac number, because 28236939 - 2⁷ = 28236811 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28236939.

It is not an unprimeable number, because it can be changed into a prime (28236959) 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, 91824 + ... + 92130.

It is an arithmetic number, because the mean of its divisors is an integer number (1300992).

Almost surely, 2^28236939 is an apocalyptic number.

28236939 is a deficient number, since it is larger than the sum of its proper divisors (13394805).

28236939 is a wasteful number, since it uses less digits than its factorization.

28236939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 407.

The product of its digits is 139968, while the sum is 42.

The square root of 28236939 is about 5313.8440887930. The cubic root of 28236939 is about 304.5130238362.

The spelling of 28236939 in words is "twenty-eight million, two hundred thirty-six thousand, nine hundred thirty-nine".