28004819 has 4 divisors (see below), whose sum is σ = 28761744. Its totient is φ = 27247896.

The previous prime is 28004813. The next prime is 28004833. The reversal of 28004819 is 91840082.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28004819 - 2¹⁶ = 27939283 is a prime.

It is a super-2 number, since 2×28004819² = 1568539774445522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28004813) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 378407 + ... + 378480.

It is an arithmetic number, because the mean of its divisors is an integer number (7190436).

Almost surely, 2^28004819 is an apocalyptic number.

28004819 is a deficient number, since it is larger than the sum of its proper divisors (756925).

28004819 is an equidigital number, since it uses as much as digits as its factorization.

28004819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 756924.

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 28004819 is about 5291.9579552374. The cubic root of 28004819 is about 303.6763168100.

The spelling of 28004819 in words is "twenty-eight million, four thousand, eight hundred nineteen".