28904939 has 8 divisors (see below), whose sum is σ = 33527808. Its totient is φ = 24405480.

The previous prime is 28904923. The next prime is 28904963. The reversal of 28904939 is 93940982.

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 28904939 - 2⁴ = 28904923 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28904939.

It is not an unprimeable number, because it can be changed into a prime (28904969) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30347 + ... + 31284.

It is an arithmetic number, because the mean of its divisors is an integer number (4190976).

Almost surely, 2^28904939 is an apocalyptic number.

28904939 is a deficient number, since it is larger than the sum of its proper divisors (4622869).

28904939 is an equidigital number, since it uses as much as digits as its factorization.

28904939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61705.

The product of its (nonzero) digits is 139968, while the sum is 44.

The square root of 28904939 is about 5376.3313699957. The cubic root of 28904939 is about 306.8956168096.

The spelling of 28904939 in words is "twenty-eight million, nine hundred four thousand, nine hundred thirty-nine".