28802221 has 4 divisors (see below), whose sum is σ = 32916832. Its totient is φ = 24687612.

The previous prime is 28802173. The next prime is 28802237. The reversal of 28802221 is 12220882.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28802221 - 2⁷ = 28802093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28802281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2057295 + ... + 2057308.

It is an arithmetic number, because the mean of its divisors is an integer number (8229208).

Almost surely, 2^28802221 is an apocalyptic number.

It is an amenable number.

28802221 is a deficient number, since it is larger than the sum of its proper divisors (4114611).

28802221 is an equidigital number, since it uses as much as digits as its factorization.

28802221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4114610.

The product of its (nonzero) digits is 1024, while the sum is 25.

The square root of 28802221 is about 5366.7700714676. The cubic root of 28802221 is about 306.5316522607.

The spelling of 28802221 in words is "twenty-eight million, eight hundred two thousand, two hundred twenty-one".