28784220 has 48 divisors (see below), whose sum is σ = 80831520. Its totient is φ = 7653376.

The previous prime is 28784207. The next prime is 28784227. The reversal of 28784220 is 2248782.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28784227) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35176 + ... + 35984.

It is an arithmetic number, because the mean of its divisors is an integer number (1683990).

Almost surely, 2^28784220 is an apocalyptic number.

28784220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28784220 is an abundant number, since it is smaller than the sum of its proper divisors (52047300).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28784220 is a wasteful number, since it uses less digits than its factorization.

28784220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1414 (or 1412 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 33.

The square root of 28784220 is about 5365.0927298603. The cubic root of 28784220 is about 306.4677795683.

The spelling of 28784220 in words is "twenty-eight million, seven hundred eighty-four thousand, two hundred twenty".