28004225 has 24 divisors (see below), whose sum is σ = 36640512. Its totient is φ = 21190400.

The previous prime is 28004213. The next prime is 28004231. The reversal of 28004225 is 52240082.

It is not a de Polignac number, because 28004225 - 2⁴ = 28004209 is a prime.

It is a hoax number, since the sum of its digits (23) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (23).

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 28004225.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 64760 + ... + 65190.

It is an arithmetic number, because the mean of its divisors is an integer number (1526688).

Almost surely, 2^28004225 is an apocalyptic number.

28004225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28004225 is a deficient number, since it is larger than the sum of its proper divisors (8636287).

28004225 is a wasteful number, since it uses less digits than its factorization.

28004225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 577 (or 572 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 23.

The square root of 28004225 is about 5291.9018320449. The cubic root of 28004225 is about 303.6741697390.

The spelling of 28004225 in words is "twenty-eight million, four thousand, two hundred twenty-five".